feat(simulation): feature-name pipeline wired + legacy window_granularity u32 retired (T-1169, T-1159)

One commit for two tickets whose changes share the bridge/plugin
plumbing files. T-1169 connects the three dormant feature-name pieces:
atlas_feature_names populated at regen (17,891 rows — 15,190 mountain,
2,701 river — via populate_atlas_feature_names mirroring the city-names
importer; systems.db regenerated, stamp fresh), attach_feature_names
wired into the cascade's Topography block with name pools threaded
DB-free through AnalyzeBody (D-225 pattern) and assignments stored on
Layer1Output/BodyWorldState for future consumers, and a
FeatureNamesRequest/Response read proxy as the bridge's 7th tagged
envelope (D-236 pattern, both SimBridge impls). Client label DRAW is
deliberately NOT here — implementation proved both river and mountain
labels need a wire-carried position (the pool is position-free; course
polylines aren't correlated with the named attractors by construction) —
deferred to T-1195's single design pass. cascade_layer1 golden re-pinned
(additive feature_names field).

T-1159 retires the legacy u32 granularity field fully shadowed by
window_granularity_v2: AtlasLayerRequest.window_granularity,
DistrictWindowLayer.granularity echo, the u32::MAX sentinel, and
resolve_window_granularity are gone server-side; client encode paths and
the caller-less atlas_window_cache legacy key component dropped;
msgpack fixtures regenerated; the T-1150 aliasing regression test now
drives through the surviving enum field. The district_window carrier
itself survives byte-compatible per D-255(c).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

client/scripts/autoloads/sim_bridge.gd

@@ -434,21 +434,22 @@ func send_named_action(action_name: String, action_data: Variant = null) -> void
 ## whole-body-layer caller (show_body()'s existing request), so their wire
 ## traffic is byte-unchanged.
 ##
-## window_granularity/window_min_wl_m (T-1150): struct/key plumbing for the
-## zoom-ladder quarter rung — district (0/omitted) stays the default for
-## every caller in this codebase today.
+## window_min_wl_m (T-1150): struct/key plumbing for the octave cutoff — 0
+## (omitted) stays the default for every caller in this codebase today.
 ##
-## window_granularity_v2 (T-1152/T-1153): the R5-redesigned string-tag
-## granularity ("Quarter"/"District"/"Region") — the ONLY way to request the
-## coarser-than-district Region rung the legacy u32 field cannot express.
-## Empty string (omitted) is the default for every caller that doesn't pass
-## it, byte-compatible with every pre-T-1152 request.
+## window_granularity_v2 (T-1152/T-1153): the string-tag granularity
+## ("Quarter"/"District"/"Region") — the way to request the coarser-than-
+## district Region rung. Empty string (omitted) is the default for every
+## caller that doesn't pass it, resolving to District server-side.
+##
+## T-1159: the legacy `window_granularity: int` parameter this function used
+## to also forward is retired — see atlas_map_protocol.gd's
+## encode_atlas_layer_request doc for the full rationale.
 func request_atlas_layers(
 	body_id: String,
 	up_to: String = "Topography",
 	window_center: Variant = null,
 	window_n: int = 0,
-	window_granularity: int = 0,
 	window_min_wl_m: int = 0,
 	window_granularity_v2: String = ""
 ) -> void:
@@ -459,7 +460,6 @@ func request_atlas_layers(
 		up_to,
 		window_center,
 		window_n,
-		window_granularity,
 		window_min_wl_m,
 		window_granularity_v2
 	)

client/scripts/protocol/atlas_map_protocol.gd

@@ -32,29 +32,27 @@ class_name AtlasMapProtocol
 ## client-side default/cap constants (DISTRICT_WINDOW_DEFAULT_N/MAX_N) live on
 ## the regional-window viewer, not duplicated into the codec.
 ##
-## `window_granularity`/`window_min_wl_m` (T-1150): the derivation-granularity
-## axis (district=1/omitted vs. quarter=4) and the octave cutoff, in whole
-## metres. Both OMITTED (not sent as 0) when at their default — this is
-## struct/key plumbing only (T-1150 scope): no caller in this codebase
-## requests quarter granularity yet (that's T-1153); this function just makes
-## it possible to ask, byte-compatible with every existing caller that
-## doesn't pass them.
+## `window_min_wl_m` (T-1150): the octave cutoff, in whole metres. OMITTED
+## (not sent as 0) when at its default — struct/key plumbing, byte-compatible
+## with every existing caller that doesn't pass it.
 ##
 ## `window_granularity_v2` (T-1152, R5 redesign — see
-## server/src/atlas/layer_proxy.rs's `WindowGranularity` doc): the ONLY way to
-## express a coarser-than-district rung (`"Region"`) the legacy `u32` field
-## cannot encode. A plain STRING variant tag ("Quarter" | "District" |
+## server/src/atlas/layer_proxy.rs's `WindowGranularity` doc): the derivation
+## granularity, a plain STRING variant tag ("Quarter" | "District" |
 ## "Region"), matching `RoadNodeKind`'s existing wire precedent on this same
 ## carrier (a bare `#[derive(Serialize, Deserialize)]` enum with no
 ## `#[serde(rename_all)]` — rmp_serde encodes the Rust variant NAME verbatim,
 ## not an integer discriminant). OMITTED (not sent as "") when
 ## `window_granularity_v2` is the empty string — `#[serde(default)]` on the
-## Rust side decodes absence as `None`, falling back to the legacy `u32`
-## field's `resolve_window_granularity_v2()` precedence rule (that field wins
-## over the legacy one whenever present — see that Rust doc for the full
-## precedence contract). Every pre-T-1152 caller (and every T-1150 caller that
-## only ever sends `window_granularity`) omits this field entirely and stays
-## byte-compatible.
+## Rust side decodes absence as `None`, resolving to District (the default
+## rung).
+##
+## **T-1159:** the legacy `window_granularity: int` field this codec used to
+## also encode (T-1150's finer-than-district-only `u32` wire encoding) is
+## retired — `window_granularity_v2` fully shadowed it since T-1152, and no
+## caller in this codebase (nor any external client — single-repo
+## client/server pair) ever sent it as anything but the byte-compatible
+## default.
 ##
 ## **Quantization split (PR #191 review, Hoshe 1 / Tyre C3):** `window_min_wl_m`
 ## is sent HERE as a raw, unquantized value — this codec does NOT snap it to
@@ -71,7 +69,6 @@ static func encode_atlas_layer_request(
 	up_to: String = "Topography",
 	window_center: Variant = null,
 	window_n: int = 0,
-	window_granularity: int = 0,
 	window_min_wl_m: int = 0,
 	window_granularity_v2: String = ""
 ) -> PackedByteArray:
@@ -80,8 +77,6 @@ static func encode_atlas_layer_request(
 		var center: Vector2i = window_center
 		msg["window_center"] = [center.x, center.y]
 		msg["window_n"] = window_n
-		if window_granularity != 0:
-			msg["window_granularity"] = window_granularity
 		if window_min_wl_m != 0:
 			msg["window_min_wl_m"] = window_min_wl_m
 		if not window_granularity_v2.is_empty():

client/scripts/protocol/protocol.gd

@@ -786,17 +786,18 @@ static func encode_request_bookmark_catalog() -> PackedByteArray:
 ## windowed district-resolution regional-map query — see
 ## atlas_map_protocol.gd's encode_atlas_layer_request doc for the wire shape.
 ## Omitted callers (every whole-body-layer call site predating T-1138) are
-## byte-unchanged. window_granularity/window_min_wl_m (T-1150): same
-## byte-compatibility contract, see atlas_map_protocol.gd.
-## window_granularity_v2 (T-1152): the R5-redesigned string-tag granularity
-## ("Quarter"/"District"/"Region") — the only way to request the Region rung.
-## Omitted (empty string) by every caller that doesn't pass it.
+## byte-unchanged. window_min_wl_m (T-1150): same byte-compatibility
+## contract, see atlas_map_protocol.gd.
+## window_granularity_v2 (T-1152): the string-tag granularity
+## ("Quarter"/"District"/"Region"). Omitted (empty string) by every caller
+## that doesn't pass it, resolving to District server-side. T-1159: the
+## legacy `window_granularity: int` parameter this used to also forward is
+## retired — see atlas_map_protocol.gd's encode_atlas_layer_request doc.
 static func encode_atlas_layer_request(
 	body_id: String,
 	up_to: String = "Topography",
 	window_center: Variant = null,
 	window_n: int = 0,
-	window_granularity: int = 0,
 	window_min_wl_m: int = 0,
 	window_granularity_v2: String = ""
 ) -> PackedByteArray:
@@ -806,7 +807,6 @@ static func encode_atlas_layer_request(
 		up_to,
 		window_center,
 		window_n,
-		window_granularity,
 		window_min_wl_m,
 		window_granularity_v2
 	)

client/tests/test_atlas_data_delivery.gd

@@ -214,35 +214,32 @@ func test_encode_atlas_layer_request_carries_window_params() -> void:
 	assert_that(decoded.value.get("window_n")).is_equal(32)
 
 
-## T-1150: window_granularity/window_min_wl_m are OMITTED (not sent as 0)
-## when at their default — a windowed request that doesn't pass them (every
-## pre-T-1150 window caller) is byte-identical to pre-T-1150 wire traffic,
-## same contract as window_center/window_n's own default-omission above.
-func test_encode_atlas_layer_request_omits_granularity_and_min_wl_by_default() -> void:
+## T-1150: window_min_wl_m is OMITTED (not sent as 0) when at its default —
+## a windowed request that doesn't pass it (every pre-T-1150 window caller)
+## is byte-identical to pre-T-1150 wire traffic, same contract as
+## window_center/window_n's own default-omission above.
+func test_encode_atlas_layer_request_omits_min_wl_by_default() -> void:
 	var bytes := Protocol.encode_atlas_layer_request(
 		"GJ1c", "Topography", Vector2i(140, 260), 32
 	)
 	var decoded = Messagepack.decode(bytes)
-	assert_bool(decoded.value.has("window_granularity")).is_false()
 	assert_bool(decoded.value.has("window_min_wl_m")).is_false()
 
 
-## T-1150: a quarter-granularity request with an octave cutoff carries both
-## new fields verbatim, unclamped (the server owns
-## resolve_window_granularity()/clamp_window_n() — never trusted from the
-## wire, same posture as window_n).
-func test_encode_atlas_layer_request_carries_granularity_and_min_wl() -> void:
+## T-1150: a request with an octave cutoff carries it verbatim, unclamped
+## (the server owns quantize_min_wl_m() — never trusted from the wire, same
+## posture as window_n).
+func test_encode_atlas_layer_request_carries_min_wl() -> void:
 	var bytes := Protocol.encode_atlas_layer_request(
-		"GJ1c", "Topography", Vector2i(140, 260), 32, 4, 512
+		"GJ1c", "Topography", Vector2i(140, 260), 32, 512
 	)
 	var decoded = Messagepack.decode(bytes)
-	assert_that(decoded.value.get("window_granularity")).is_equal(4)
 	assert_that(decoded.value.get("window_min_wl_m")).is_equal(512)
 
 
 ## T-1152/T-1153: window_granularity_v2 is OMITTED (not sent as "") when at
 ## its empty-string default — same byte-compatibility contract as
-## window_granularity/window_min_wl_m's own default-omission.
+## window_min_wl_m's own default-omission.
 func test_encode_atlas_layer_request_omits_granularity_v2_by_default() -> void:
 	var bytes := Protocol.encode_atlas_layer_request(
 		"GJ1c", "Topography", Vector2i(140, 260), 32
@@ -252,22 +249,20 @@ func test_encode_atlas_layer_request_omits_granularity_v2_by_default() -> void:
 
 
 ## T-1152/T-1153: a Region-rung request carries window_granularity_v2 as the
-## bare string "Region" — the ONLY way to express the coarser-than-district
-## rung (WindowGranularity's Rust doc: "the ONLY way to actually request
-## Region is window_granularity_v2 = Some(WindowGranularity::Region)"), a
-## plain rmp_serde variant-name encoding matching RoadNodeKind's existing
-## wire precedent, NOT an integer discriminant.
+## bare string "Region" — the way to express the coarser-than-district rung
+## (WindowGranularity's Rust doc), a plain rmp_serde variant-name encoding
+## matching RoadNodeKind's existing wire precedent, NOT an integer
+## discriminant.
+##
+## T-1159: the legacy `window_granularity: int` param this call used to also
+## pass positionally (between window_n and window_min_wl_m) is retired — see
+## atlas_map_protocol.gd's encode_atlas_layer_request doc.
 func test_encode_atlas_layer_request_carries_granularity_v2_region() -> void:
 	var bytes := Protocol.encode_atlas_layer_request(
-		"GJ1c", "Topography", Vector2i(0, 0), 6400, 0, 0, "Region"
+		"GJ1c", "Topography", Vector2i(0, 0), 6400, 0, "Region"
 	)
 	var decoded = Messagepack.decode(bytes)
 	assert_that(decoded.value.get("window_granularity_v2")).is_equal("Region")
-	# The legacy window_granularity field is independently omittable — a
-	# Region request sends ONLY the v2 tag, never a legacy value pretending
-	# to mean something for Region (WINDOW_GRANULARITY_REGION_KEY is a
-	# key-space tag the SERVER echoes, never a legal wire INPUT).
-	assert_bool(decoded.value.has("window_granularity")).is_false()
 
 
 ## §2: district_window is a distinct payload (echoes center/n for the
@@ -280,7 +275,7 @@ func test_atlas_response_district_window_passthrough() -> void:
 	var window := {
 		"center": [140, 260],
 		"n": 32,
-		"granularity": 4,  # T-1150: quarter granularity, passed through same as every other field
+		"granularity_v2": "Quarter",
 		"min_wl_m": 512,
 		"morphology": PackedByteArray([8, 14, 0, 5]),
 		"elev_q": PackedByteArray([40, 62, 5, 88]),
@@ -307,7 +302,6 @@ func test_atlas_response_district_window_passthrough_region_rung() -> void:
 	var window := {
 		"center": [0, 0],
 		"n": 6400,
-		"granularity": 4294967295,  # WINDOW_GRANULARITY_REGION_KEY (u32::MAX) — key-space tag, not a real multiplier
 		"granularity_v2": "Region",
 		"min_wl_m": 0,
 		"morphology": PackedByteArray([8, 14, 0, 5]),

client/tests/test_atlas_window_cache.gd

@@ -122,100 +122,58 @@ func test_clear_empties_the_cache() -> void:
 
 
 # =============================================================================
-# granularity / min_wl_m (T-1150, zoom ladder design doc §3 aliasing risk)
+# min_wl_m (T-1150, zoom ladder design doc §3 aliasing risk)
 # =============================================================================
 
 
-## **MANDATORY aliasing regression (client half, T-1150):** a granularity-4
-## (quarter) key and a granularity-1 (district) key at the IDENTICAL
-## (body_id, center, n) must be DISTINCT cache keys — this is what prevents a
-## quarter-spacing request from silently reading (or overwriting) a
-## district-spacing window's cache entry, and vice versa.
-func test_make_key_distinguishes_granularity_at_identical_body_center_n() -> void:
-	var k_district := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY
-	)
-	var k_quarter := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 4)
-	assert_str(k_district).is_not_equal(k_quarter)
-
-
-## Same aliasing risk, the other new axis: two requests identical except for
-## `min_wl_m` (the octave cutoff) must not collide either — different cutoffs
-## are different derived payloads (T-1149/T-1150).
-func test_make_key_distinguishes_min_wl_m_at_identical_body_center_n_granularity() -> void:
-	var k_uncut := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0
-	)
-	var k_cut := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 512
-	)
+## **MANDATORY aliasing regression (client half, T-1150):** two requests
+## identical except for `min_wl_m` (the octave cutoff) must not collide —
+## different cutoffs are different derived payloads (T-1149/T-1150).
+func test_make_key_distinguishes_min_wl_m_at_identical_body_center_n() -> void:
+	var k_uncut := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 0)
+	var k_cut := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 512)
 	assert_str(k_uncut).is_not_equal(k_cut)
 
 
-## Omitting granularity/min_wl_m (every pre-T-1150 call site) must produce the
-## SAME key as passing the explicit district/no-cutoff defaults — byte/string
-## compatibility for existing callers, not just "doesn't crash".
-func test_omitted_granularity_and_min_wl_m_match_explicit_district_defaults() -> void:
+## Omitting min_wl_m (every pre-T-1150 call site) must produce the SAME key
+## as passing the explicit no-cutoff default — byte/string compatibility for
+## existing callers, not just "doesn't crash".
+func test_omitted_min_wl_m_matches_explicit_default() -> void:
 	var k_omitted := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32)
-	var k_explicit := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0
-	)
+	var k_explicit := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 0)
 	assert_str(k_omitted).is_equal(k_explicit)
 
 
-## End-to-end through put()/get_window()/has() (not just make_key() in
-## isolation): a quarter-granularity window and a district-granularity window
-## at the identical (body, center, n) must both be independently retrievable,
-## neither one clobbering or masking the other.
-func test_district_and_quarter_windows_coexist_at_identical_body_center_n() -> void:
-	var cache := AtlasWindowCache.new()
-	var district_window := {"granularity": AtlasWindowCache.DISTRICT_GRANULARITY, "id": "district"}
-	var quarter_window := {"granularity": 4, "id": "quarter"}
-
-	cache.put("GJ1c", Vector2i(10, 20), 32, district_window, AtlasWindowCache.DISTRICT_GRANULARITY)
-	cache.put("GJ1c", Vector2i(10, 20), 32, quarter_window, 4)
-
-	assert_int(cache.size()).is_equal(2)
-	assert_that(
-		cache.get_window("GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY)
-	).is_equal(district_window)
-	assert_that(cache.get_window("GJ1c", Vector2i(10, 20), 32, 4)).is_equal(quarter_window)
-
-
 # =============================================================================
 # granularity_v2 (T-1152/T-1153): the string-tag axis — the ONLY thing that
-# distinguishes Region from District/Quarter, since Region has no legal
-# legacy-int representation (WindowGranularity::legacy_u32() returns None for
-# Region — see the server's own doc). This is the SAME mandatory-aliasing
-# regression class as the granularity/min_wl_m tests above, extended to the
-# new axis.
+# distinguishes Region from District/Quarter (WindowGranularity has no
+# integer representation at all — see the server's own doc). This is the
+# SAME mandatory-aliasing regression class as the min_wl_m tests above,
+# extended to the new axis.
+#
+# T-1159: these tests used to also carry a legacy int `granularity`
+# positional argument (mirroring the server's now-retired
+# `window_granularity: u32` wire field) — removed along with the cache's own
+# legacy key component (see atlas_window_cache.gd's doc).
 # =============================================================================
 
 
 ## **MANDATORY aliasing regression (T-1152/T-1153):** a Region-rung key and a
-## District-rung key at the IDENTICAL (body_id, center, n, legacy
-## granularity, min_wl_m) must be DISTINCT cache keys — the legacy int slot
-## alone (both "District" and default-omitted callers pass
-## DISTRICT_GRANULARITY=1) cannot tell them apart; granularity_v2 is what
-## does.
+## District-rung key at the IDENTICAL (body_id, center, n, min_wl_m) must be
+## DISTINCT cache keys — granularity_v2 is the only axis that can tell them
+## apart.
 func test_make_key_distinguishes_granularity_v2_region_from_district() -> void:
-	var k_district := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0, "District"
-	)
-	var k_region := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0, "Region"
-	)
+	var k_district := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 0, "District")
+	var k_region := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 0, "Region")
 	assert_str(k_district).is_not_equal(k_region)
 
 
 ## Omitting granularity_v2 (every pre-T-1152 call site) must produce the SAME
 ## key as passing the explicit "District" default — byte/string
-## compatibility, same contract as the legacy granularity/min_wl_m defaults.
+## compatibility, same contract as the min_wl_m default above.
 func test_omitted_granularity_v2_matches_explicit_district_default() -> void:
 	var k_omitted := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32)
-	var k_explicit := AtlasWindowCache.make_key(
-		"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0, "District"
-	)
+	var k_explicit := AtlasWindowCache.make_key("GJ1c", Vector2i(10, 20), 32, 0, "District")
 	assert_str(k_omitted).is_equal(k_explicit)
 
 
@@ -229,23 +187,13 @@ func test_region_and_district_windows_coexist_at_identical_body_center_n() -> vo
 	var district_window := {"granularity_v2": "District", "id": "district"}
 	var region_window := {"granularity_v2": "Region", "id": "region"}
 
-	cache.put(
-		"GJ1c", Vector2i(10, 20), 32, district_window, AtlasWindowCache.DISTRICT_GRANULARITY, 0,
-		"District"
-	)
-	cache.put(
-		"GJ1c", Vector2i(10, 20), 32, region_window, AtlasWindowCache.DISTRICT_GRANULARITY, 0,
-		"Region"
-	)
+	cache.put("GJ1c", Vector2i(10, 20), 32, district_window, 0, "District")
+	cache.put("GJ1c", Vector2i(10, 20), 32, region_window, 0, "Region")
 
 	assert_int(cache.size()).is_equal(2)
 	assert_that(
-		cache.get_window(
-			"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0, "District"
-		)
+		cache.get_window("GJ1c", Vector2i(10, 20), 32, 0, "District")
 	).is_equal(district_window)
 	assert_that(
-		cache.get_window(
-			"GJ1c", Vector2i(10, 20), 32, AtlasWindowCache.DISTRICT_GRANULARITY, 0, "Region"
-		)
+		cache.get_window("GJ1c", Vector2i(10, 20), 32, 0, "Region")
 	).is_equal(region_window)

client/tests/test_protocol.gd

@@ -512,13 +512,17 @@ func test_decode_atlas_response_not_found() -> void:
 
 
 ## PR #191 review, Hoshe 3: `atlas_response_ready_with_window.msgpack` had NO
-## consumer anywhere in client/tests — regenerated by the T-1150 `granularity`/
-## `min_wl_m` field additions but nothing decoded it through the real IPC path.
-## This is that consumer, matching the sibling `test_decode_atlas_response_*`
-## tests' style/fixture-dir convention above: full decode_atlas_layer_response()
+## consumer anywhere in client/tests — regenerated by the T-1150 `min_wl_m`
+## field addition but nothing decoded it through the real IPC path. This is
+## that consumer, matching the sibling `test_decode_atlas_response_*` tests'
+## style/fixture-dir convention above: full decode_atlas_layer_response()
 ## round trip (not a hand-built Dictionary like test_atlas_data_delivery.gd's
-## passthrough tests), confirming `district_window.granularity`/`.min_wl_m`
-## (T-1150's two new echo fields) survive the real client decode path.
+## passthrough tests), confirming `district_window.granularity_v2`/`.min_wl_m`
+## survive the real client decode path.
+##
+## T-1159: the legacy `district_window.granularity` int echo this test used
+## to also assert is retired server-side — see
+## server/src/atlas/layer_proxy.rs's `DistrictWindowLayer` doc.
 func test_decode_atlas_response_ready_with_window() -> void:
 	var bytes := _load_fixture("atlas_response_ready_with_window")
 	var resp = Protocol.decode_atlas_layer_response(bytes)
@@ -528,7 +532,7 @@ func test_decode_atlas_response_ready_with_window() -> void:
 	var window: Dictionary = resp.district_window
 	assert_that(window.get("center")).is_equal([10, -5])
 	assert_that(int(window.get("n"))).is_equal(2)
-	assert_that(int(window.get("granularity"))).is_equal(1)
+	assert_that(str(window.get("granularity_v2"))).is_equal("District")
 	assert_that(int(window.get("min_wl_m"))).is_equal(0)
 
 

client/ui/implant/apps/atlas/atlas_window_cache.gd

@@ -2,27 +2,30 @@ extends RefCounted
 
 ## Client-side LRU cache for DistrictWindowLayer responses (T-1138, D-226
 ## T-1124 amendment §4 "Client cache policy"; extended T-1150 for the
-## granularity/min_wl axes; extended T-1152/T-1153 for the granularity_v2
-## string-tag axis that makes Region representable at all).
+## min_wl axis; extended T-1152/T-1153 for the granularity_v2 string-tag
+## axis that makes Region representable at all).
 ##
-## Keyed on (body_id, center, n, granularity, min_wl_m, granularity_v2) —
-## D-227's determinism guarantee (same seed + body + position + derivation
-## params -> same derived output, always) means a previously-fetched window is
-## valid FOREVER for that body+seed. This is an LRU-evict-only cache: no
-## freshness check, no TTL, no invalidation path at all. The only reason an
-## entry ever leaves is capacity pressure.
+## Keyed on (body_id, center, n, min_wl_m, granularity_v2) — D-227's
+## determinism guarantee (same seed + body + position + derivation params ->
+## same derived output, always) means a previously-fetched window is valid
+## FOREVER for that body+seed. This is an LRU-evict-only cache: no freshness
+## check, no TTL, no invalidation path at all. The only reason an entry ever
+## leaves is capacity pressure.
 ##
-## granularity/min_wl_m/granularity_v2 default to
-## DISTRICT_GRANULARITY/0/DEFAULT_GRANULARITY_V2 ("District", district
-## spacing, no octave cutoff) — every pre-T-1150 caller that doesn't pass them
-## keeps its existing key shape and cache behavior unchanged. This is the
-## client half of the mandatory aliasing fix (T-1150 design doc §3, extended
+## min_wl_m/granularity_v2 default to 0/DEFAULT_GRANULARITY_V2 ("District",
+## no octave cutoff) — every pre-T-1150 caller that doesn't pass them keeps
+## its existing key shape and cache behavior unchanged. This is the client
+## half of the mandatory aliasing fix (T-1150 design doc §3, extended
 ## T-1152): a quarter-granularity request, a district-granularity request,
 ## and a REGION-granularity request all at the identical (body, center, n)
-## MUST NOT collide on the same cache slot — the legacy int alone cannot
-## distinguish Region (it has no legal legacy-int value, see
-## GRANULARITY_V2_REGION's doc), which is exactly why granularity_v2 is a
-## SEPARATE key component rather than a replacement for the legacy one.
+## MUST NOT collide on the same cache slot — granularity_v2 is what
+## distinguishes them.
+##
+## **T-1159:** the legacy int `granularity` key component (district=1 /
+## quarter=4, mirroring the server's now-retired `window_granularity: u32`
+## wire field) is retired — `granularity_v2` alone has always been sufficient
+## to distinguish every rung (it's the ONLY axis that can express Region at
+## all), so carrying both was redundant.
 ##
 ## Godot's Dictionary preserves insertion order, so "move to the end on
 ## touch, evict from the front on overflow" is the whole LRU implementation —
@@ -35,26 +38,16 @@ extends RefCounted
 
 const DEFAULT_MAX_ENTRIES: int = 24
 
-## Mirrors the server's WINDOW_GRANULARITY_DISTRICT (layer_proxy.rs) — the
-## default granularity every pre-T-1150 caller implicitly requests.
-const DISTRICT_GRANULARITY: int = 1
-
 ## Mirrors the server's WindowGranularity enum (T-1152, R5 redesign,
 ## layer_proxy.rs) — the string-tag vocabulary rmp_serde encodes a bare
 ## `#[derive(Serialize, Deserialize)]` enum's variant name as, verbatim (same
-## wire convention `RoadNodeKind` already established on this carrier). This
-## is the KEY-SPACE axis (T-1153): the legacy int `granularity` param below
-## stays wired for every existing District/Quarter caller (byte/behavior
-## compatible), but a cache slot is now ALSO qualified by this string so a
-## Region-rung window can never alias onto a District/Quarter slot at the
-## identical (body, center, n, legacy_granularity, min_wl_m) — the exact
-## aliasing risk the T-1150 design doc §3 flagged, extended to the new axis.
+## wire convention `RoadNodeKind` already established on this carrier).
 const GRANULARITY_V2_QUARTER: String = "Quarter"
 const GRANULARITY_V2_DISTRICT: String = "District"
 const GRANULARITY_V2_REGION: String = "Region"
-## Default v2 tag for every caller that doesn't pass one — matches
-## DISTRICT_GRANULARITY's own "district is the implicit default" contract, so
-## an omitted v2 tag and an explicit "District" tag key identically.
+## Default v2 tag for every caller that doesn't pass one — district spacing
+## is the implicit default, so an omitted v2 tag and an explicit "District"
+## tag key identically.
 const DEFAULT_GRANULARITY_V2: String = GRANULARITY_V2_DISTRICT
 
 var _max_entries: int = DEFAULT_MAX_ENTRIES
@@ -65,42 +58,37 @@ func _init(max_entries: int = DEFAULT_MAX_ENTRIES) -> void:
 	_max_entries = maxi(1, max_entries)
 
 
-## Build the cache key from the six fields D-227 + T-1150/T-1152 make
+## Build the cache key from the five fields D-227 + T-1150/T-1152 make
 ## sufficient: body_id (which world+body), center (a [row, col] pair or
-## Vector2i), n (window extent in districts), granularity (the legacy int:
-## district=1 / quarter=4), min_wl_m (the octave cutoff, 0 = none), and
-## granularity_v2 (the T-1152 string tag: "Quarter"/"District"/"Region" — the
-## axis that actually distinguishes Region from every finer rung, since
-## Region has no legal legacy-int representation and the legacy slot alone
-## cannot tell a Region window's cache entry apart from a District one at the
-## same (center, n)). String-keyed rather than a nested Dictionary/Array key
-## — Godot Dictionary keys compare by value for primitives but a consistent
-## stringification sidesteps any Vector2i-vs-Array identity mismatch between
-## what a caller happens to hand in.
+## Vector2i), n (window extent in districts), min_wl_m (the octave cutoff,
+## 0 = none), and granularity_v2 (the T-1152 string tag:
+## "Quarter"/"District"/"Region"). String-keyed rather than a nested
+## Dictionary/Array key — Godot Dictionary keys compare by value for
+## primitives but a consistent stringification sidesteps any
+## Vector2i-vs-Array identity mismatch between what a caller happens to hand
+## in.
 static func make_key(
 	body_id: String,
 	center: Vector2i,
 	n: int,
-	granularity: int = DISTRICT_GRANULARITY,
 	min_wl_m: int = 0,
 	granularity_v2: String = DEFAULT_GRANULARITY_V2
 ) -> String:
-	return "%s:%d,%d:%d:%d:%d:%s" % [
-		body_id, center.x, center.y, n, granularity, min_wl_m, granularity_v2
+	return "%s:%d,%d:%d:%d:%s" % [
+		body_id, center.x, center.y, n, min_wl_m, granularity_v2
 	]
 
 
 ## True if a window is already cached for this exact (body, center, n,
-## granularity, min_wl_m, granularity_v2).
+## min_wl_m, granularity_v2).
 func has(
 	body_id: String,
 	center: Vector2i,
 	n: int,
-	granularity: int = DISTRICT_GRANULARITY,
 	min_wl_m: int = 0,
 	granularity_v2: String = DEFAULT_GRANULARITY_V2
 ) -> bool:
-	return _entries.has(make_key(body_id, center, n, granularity, min_wl_m, granularity_v2))
+	return _entries.has(make_key(body_id, center, n, min_wl_m, granularity_v2))
 
 
 ## Fetch a cached window, touching it (move-to-most-recently-used). Returns
@@ -112,11 +100,10 @@ func get_window(
 	body_id: String,
 	center: Vector2i,
 	n: int,
-	granularity: int = DISTRICT_GRANULARITY,
 	min_wl_m: int = 0,
 	granularity_v2: String = DEFAULT_GRANULARITY_V2
 ) -> Variant:
-	var key := make_key(body_id, center, n, granularity, min_wl_m, granularity_v2)
+	var key := make_key(body_id, center, n, min_wl_m, granularity_v2)
 	if not _entries.has(key):
 		return null
 	var value: Variant = _entries[key]
@@ -133,11 +120,10 @@ func put(
 	center: Vector2i,
 	n: int,
 	window: Dictionary,
-	granularity: int = DISTRICT_GRANULARITY,
 	min_wl_m: int = 0,
 	granularity_v2: String = DEFAULT_GRANULARITY_V2
 ) -> void:
-	var key := make_key(body_id, center, n, granularity, min_wl_m, granularity_v2)
+	var key := make_key(body_id, center, n, min_wl_m, granularity_v2)
 	if _entries.has(key):
 		_entries.erase(key)
 	_entries[key] = window