docs(meta): D-166 amendment — seamless Atlas zoom ladder is a hard Phase-4 deliverable condition

Jeroen's ruling from the Groombridge/Lendel zoom-ladder captures: the BHAG
stays 'a Reach a character can travel through'; the Phase 4 exit bar now
additionally requires a continuous Atlas zoom ladder (planetary map -> tile
scale, each level deterministically derived at native granularity, never
magnified interpolation). Evidence in the record: the 16-district window is
sub-pixel vs its heightmap source at Lendel scale, so everything below fit
zoom is D-227 invented detail that must be derived, not smoothed.

CLAUDE.md Phase-4 row carries the condition; T-1143 (the ladder design
pass) appended + raised to high — it and the D-226(d) floor question are
now phase-gating.

governance/decisions/architecture.md

@@ -601,6 +601,7 @@ Technical foundation decisions that constrain implementation: engine, client-ser
 
 - **Amendment (2026-05-22):** Phases 4 and 5 swapped — **world generation now precedes player control**. The rule: no player-control or in-world rendering work begins until the generator can deterministically seed-generate every tile of every world via the full multilayer cascade. The original Phase 4 "2-floor test map" is **dropped** — test layers are produced by the generator itself once layer-drawing begins; we start drawing the world only when generation knows what to draw. Generation progress is viewed as **per-layer maps in the implant Atlas** (the Phase 3 deliverable, already built), not via an in-world renderer. The existing in-world rendering code is **left as-is until Phase 5** — neither built upon nor removed before then. Rationale: building player systems against a throwaway test substrate means rebuilding them against real generated tiles later; gating player work on deterministic generation avoids that waste. Epics T-749 (now Phase 5) and T-750 (now Phase 4) and the CLAUDE.md cascade table are updated to match.
 - **Amendment (2026-06-12):** Build order **within and after** the cascade clarified (Jeroen). The world is built **outside-in**: (1) geo layer; (2) the economic layer drawn onto the world — cities, buildings, streets, blocks, and the inter-settlement road/rail network; (3) building templates; (4) **door boundary contracts** defining the seam between exteriors and building interiors. Only then (5) the background NPC layer and building interiors (Phase 6), and only after that does gameplay/scenario design resume ("making it a game again" — tracked in the post-cascade gameplay parking epic, outside any phase). **Player control and visual rendering (Phase 5) ramp in parallel once outside generation produces walkable exteriors** — the Phase-5 trigger is "outsides generate deterministically and are walkable", not "all Phase-4 polish complete"; T-962 holds the gate and is updated to this trigger. Guiding statement: *"Before this is a game I want it to be a Reach a character can travel through."* NPCs, scenarios, and gameplay systems are conceived, designed, and built only after the traversable world exists. This amendment absorbs the v0.2 scope cluster — D-114, D-115, D-117, D-118, D-120 are marked superseded by this record, with each one's surviving design substance noted on the record itself.
+- **Amendment (2026-07-21):** **Seamless zoom ladder is a hard Phase-4 deliverable condition** (Jeroen, reviewing the Groombridge/Lendel Atlas zoom-ladder captures). The guiding statement (BHAG) is deliberately **unchanged** — *"Before this is a game I want it to be a Reach a character can travel through."* What changes is the Phase 4 exit bar: the Atlas must provide a **continuous zoom ladder from the planetary map down to tile scale**, where every zoom level shows **deterministically calculated information at that level's native granularity** ("LoD on the information in view" — the T-1143 ruling), never magnified interpolation of a coarser composite. Evidence that forced the condition: at Lendel's scale one heightmap pixel spans ~19 districts, so the 16-district window is *sub-pixel* relative to its source — beyond fit-zoom the current viewer can only linearly magnify the same 16×16 composite (captures 2026-07-21, `.cache/screenshots/groombridge/`), and the real waterline sat ~36 districts from the pixel-edge estimate, i.e. **all** information at window scale and below is invented detail (D-227) that must be *derived*, not smoothed. T-1143 is the design pass for the ladder (granularity rungs, wire budget, the D-226(d) floor question); the Phase-4 epic (T-750) does not close until the ladder stands. CLAUDE.md's cascade table is updated to carry the condition.
 - **Rationale:** The pattern of negotiating pragmatic v0.2 cuts while discussing room-level detail repeatedly produced superseded decisions, confused agents, and distracted from building the actual product. The cascade enforces a first-things-first discipline: each layer of the game is grounded in the layer below it before detail is added.
 - **Raised by:** Jeroen, established 2026-03-24 during world generation workshop.
 - **Dissent:** None.