feat(ui): T-1145 round-2 polish — cover-fit, WASD+edge-scroll pan, smoothed composite (Jeroen rulings)

Cover-fit: fit_window_view zooms from the viewport's LARGER dimension,
no margin factor (any factor under 1.0 leaves a long-axis gap — checked
numerically) — the composite fills edge to edge, overhanging the short
axis into pan-space; the refloat center-equality early-return already
prevents refetch churn at rest (proved, not just tested).

Input model (Jeroen: drag breaks click semantics with map objects):
LMB-drag pan REMOVED from the regional window; clicks are
object-reserved. Pan = held WASD/arrows polled in _process (delta- and
zoom-scaled, camera-pans-toward-key convention verified numerically)
plus edge-scroll within 24px of the viewport border; both suppressed
over UI and on OS focus loss; both set _user_adjusted; wheel zoom and
Esc unchanged. Reads RAW physical keycodes deliberately — independent
of the shared D-054 move_* InputMap actions bound to the same keys
(whose occlusion-leak is pre-existing and now ticketed as T-1146).
Pole wall + east-west wrap unchanged, re-driven through the new
inputs; drag tests replaced, not kept.

Smoothed composite (interim pending T-1143): per-cell colors bake into
an n x n Image/ImageTexture (exact existing colorizer incl. overlay +
ice tint) drawn once with LINEAR filtering — GPU bilinear reads as
terrain, the planetary heightmap's own treatment. Crisp per-cell path
preserved behind COMPOSITE_SMOOTH for T-1143 A/B. Rebuild only on
reference-identity change of window/toggle (is_same — verified true
reference equality; value-equal distinct dicts DO rebuild).

Governance: T-1145 amendment paragraph on D-226 T-1124 SS5 (all three
supersessions); pql decisions validate ok.

Suites: window_viewer 74/74, window_geometry 32/32, window_overlay
(new) 16/16; gdlint clean on all six files.

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

governance/decisions/architecture.md

@@ -1665,6 +1665,8 @@ Technical foundation decisions that constrain implementation: engine, client-ser
     - **Overlay/legend reuse against §2–§4.** The base layer is **morphology, lightness-modulated by `elev_q`** (one `0.7 + 0.3*(elev_q/100)` multiply per cell — relief read without a second draw call, the T-1112 "shape=identity, cheap second channel=magnitude" instinct as hue=type / lightness=elevation), reusing the T-1123 probe's 17-entry `MORPHOLOGY_RGB` hues verbatim; it is always-on once the LOD threshold is crossed (it *is* this screen's `terrain` layer), so it takes no toggle id. Three switchable overlays get new `gen_dw_temp` / `gen_dw_moisture` / `gen_dw_veg` `OVERLAY_DEFS` ids (`group: "toggle"`, the `gen_l1_*` multi-toggle-over-one-base precedent): **temperature** reuses T-1118's region-grid ramp *exactly* (same `i16` deci-°C domain + `REGION_TEMP_NONE_DC` sentinel disposition — one colorizer across both zoom levels, §2's consistency ruling); **moisture** reuses the existing `SUB_BIOME_COLORS` dry-sand→wet-teal endpoints; **vegetation** is a green-family ramp with **`Marine = 6` rendered transparent** (lets the morphology water-blue show through — `Marine` is `derive_vegetation`'s bookkeeping answer for already-`OpenOcean`/`Lake` districts, not new player information; a second blue would fight or duplicate the morphology read — this is the exhaustive disposition §3 mandates). **Glaciation is a modifier, not a toggle**: an ice-tint wash gated on `glaciation_grade >= Moderate` (alpha scaling with grade; `None`/`Light` draw no tint — `Light` is erosion signatures, not visible ice, per `apply_ice_tint`'s own gate, which this corrected prose now matches — PR #187 C4) composited over whichever layer shows — the `aliveness_probe::apply_ice_tint` approach ported to the player composite; it keeps sea-ice (tint over `OpenOcean` navy → whitened blue) visually distinct from open ocean and from ice-capped land (tint over alpine grey → near-white) by alpha-compositing over different bases rather than three drifting hard-coded colors. Legend: one `GENERATION_LEGEND` entry per new id (existing data-driven `atlas_legend_panel.gd` table, no new panel class); the morphology base folds its 17 zones into ~5 family rows (water / coastal-transition / plains-river / upland / volcanic) with the full mapping in the city-click sidebar, mirroring T-1112's "not everything earns permanent screen space" discipline. Implant chrome discipline (D-169/D-170): `ImplantHeader` carries a location label (the nearest settlement's name when the window is over/near one, else a coordinate/region label — the window is not settlement-anchored, per the entry clause above) + extent-in-real-units subtitle (e.g. "4.1 × 4.1 km · 2.0 km/cell") + one optional flavor line; the map-data palettes stay **out of** the theme's semantic accent roles (especially `ACCENT_ACTIVE` gold, which the settlement marker owns and must not compete with); no scanline/glitch dressing (the implant is confident working tech — a signal-quality state, if ever needed, rides `_gen_pending_indicator`, not cosmetic noise). Full color/ramp/compositing/legibility rationale and the n=32↔n=64 on-screen-scale math live in Araminta's companion T-1124 sections (visual encoding / implant aesthetic / legibility constraints), not re-derived here.
 
   **Amended 2026-07-21 (T-1124 §5 entry revision — Jeroen, first companion hands-on):** the regional-map **entry mechanic changes from zoom-threshold LOD swap to explicit click-through**. Jeroen's ruling after using `make atlas`: the planetary pixel-scaling pan/zoom "is only messing with the pixels of the map and the interaction is weird" — (a) the **planetary heightmap view becomes FIXED** (no drag-pan / wheel-zoom of the planetary canvas; the current pan/zoom ships until T-1138 replaces it, then is removed *in the same change* as the replacement so close inspection is never stranded); (b) **entry is a click-through**: hovering the planetary heightmap shows a **rectangle cursor** representing the regional-mode bounds, and clicking descends into the regional map centered on the click point's derived `DistrictPos` — §5's float-on-center/first-window rules carry over with "pan center" read as "click point". `DISTRICT_WINDOW_MIN_ZOOM` is retired before ever being built (the T-1138 zoom-headroom note is moot); the §5 cross-reference reading of D-013 ("the zoom gesture owns spatial descent") is superseded **for this seam only** — click owns descent. Everything *inside* the regional mode stands unchanged (§4 pan-only refetch, debounce, float-on-center, D-227 cache, border-fade). A **morphing transition** between map modes is explicitly deferred (Jeroen: nice, too ambitious for now) — the descent may cut. **Open at T-1138:** the rectangle cursor is an affordance, not to scale — an n=64 window (~131 km) is a few pixels on a planetary canvas; the screen design must resolve the honest representation (rectangle at true extent with a zoom-in cut on click, or a not-to-scale reticle with the real extent labeled beside it) without implying the regional view covers more planet than it does.
+
+  **Amended 2026-07-21 (T-1145 — Jeroen, second companion hands-on, KALLAST window):** three regional-window presentation fixes, all client-only. **Cover-fit supersedes contain:** `fit_window_view()`'s zoom now derives from the LARGER viewport dimension with no margin factor (`max(viewport.x, viewport.y) / composite_native`, not the old `0.9 * min(...)`), so the square district-window composite fills a wide/tall viewport edge to edge instead of leaving side margins, with the shorter axis' data extending into pan-space (the same "cover" concept as CSS `object-fit: cover`) — the existing §4 pan-edge refetch is unaffected (it keys off the screen-center-to-DistrictPos mapping, which any fit already centers on `_held_center` by construction, so no refetch churn at rest). **WASD + edge-scroll supersedes drag-pan:** LMB-drag panning is removed entirely (Jeroen's ruling — drag conflicts with click semantics for the map objects, e.g. settlements, this window will host later); panning is now held WASD/arrow keys (continuous, frame-rate-independent, `_process`-polled, physical-keycode reads to stay independent of the project's existing `move_north`/etc. gameplay-movement InputMap actions bound to the same keys) plus edge-scrolling (cursor within ~24px of a viewport edge, suppressed over UI and while the OS window lacks focus); wheel zoom is unchanged; pole-wall (§5 amendment above) and east-west wrap (T-1142) semantics are preserved unchanged under the new input source. **Smoothing is an interim presentation, pending T-1143:** the composite renders as an `n`×`n` `Image`/`ImageTexture` (one pixel per district, the identical existing per-cell color pipeline) drawn scaled with linear filtering — the same treatment the planetary heightmap already gets — instead of `n`×`n` flat rects, so GPU bilinear sampling reads as a terrain gradient rather than hard blocks; the original crisp per-cell path survives behind a compile-time const specifically so T-1143's design pass can compare both directly, and this smoothing is **not** T-1143's answer to district-tier legibility, only a stopgap ahead of it.
 - **Rationale:** Reusing the real UI — rather than a parallel offline renderer or dumped files — means the debug/review surface never diverges from what ships, and a dropped artifact can't go stale. Agent-navigability converts qualitative "does the synthesis look natural?" review from a manual eyeball pass into an automatable sweep that flags the few outliers for a human. The harness rides seams that already exist (`TickRate::Paused`, the paused-allowlist, `gameplay_occluded`, the bridge framing, the `run-visual` capture primitive) — a naming-and-contract exercise, not a new subsystem.
 - **New surface:** server pause-gating (run-conditions on the world phases keyed to a pause command); client `AtlasAgentInterface` (`observe`/`act`, Control-tree walker) + its local transport; the generation overlay rendering + selector + legend; interactive capture wired to `run-visual`.
 - **Implementation:** Phase 4 (epic T-750), built bottom-up — auto-pause substrate, T-969 proxy (D-225), T-960 viewer, agent channel, agent capture. Geography is the first consumer.