docs(re): session log for 2026-08-11, and correct the capital-ship INDEX row

The capital-ship row still said placement was the open question. Today's work
says otherwise: placement is sound (hull static-exact, cross-id mounting is 2
pairs across 335 ships) and the user-reported "ships assemble wrong" is an XBG7
mis-decode instead. The row now says that and points at the backlog and the mesh
doc, and keeps the one-way-test problem visible.

SESSION-2026-08-11.md summarises the run for review, leading with the single item
that needs the user's decision (editing save slot 01, deliberately not done) and
separating findings, the two disc defects found, and the process notes.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/re/SESSION-2026-08-11.md

@@ -0,0 +1,69 @@
+# Session log — 2026-08-11 (autonomous run)
+
+What changed today, in the order a reviewer would want it, with the one item
+that needs **your decision** called out first.
+
+## Needs a decision from you
+
+**Editing save slot 01.** Save files can now be written back
+([savegame_edit.py](../../tools/re-capture/savegame_edit.py) re-wraps a real save
+**byte-identically**), and hand-written saves load. That unblocked several
+questions by probing throwaway slots. But the **title-menu screens read the
+auto-save (slot 01)**, so the remaining save-field questions (the difficulty
+enum, `SHAB.b`) need slot 01 itself edited — the only save with real progress.
+Not done. Recoverable (full content backup + slot 01's bytes archived), but it is
+your call. Everything else below was done in throwaway slots.
+
+## Findings, by area
+
+### Save format
+- **The develop differential**: buying one Arsenal weapon moves exactly three
+  fields — Points `+24` (which **separates it from `+28`**), clear ratio `+8`
+  (so the ratio counts *collection*, not stages), and two entries of the 54-byte
+  blob. Blob alphabet: `0` locked / `2` developable / `4` owned; only the `4`s
+  are stored, `2` is re-derived at load.
+- **The blob's index space is solved** — it follows `strings.tbl`'s item order,
+  **cut items included**, pinned by four probe saves and closing exactly at 53.
+- **`SHAB` is the per-stage record table**: record 0 = Stage 01, and `c` is its
+  best clear time in ms (`324773` = the `05:24.77` MISSION SELECT shows).
+- **Refuted**: every GHAD scalar as stage/difficulty (16 elements probed), and
+  "stage = filled `SHAB` count + 1".
+
+### Formats
+- **T8aD 96 % → 100 %** of the disc: a surface is a list of **sub-rectangles**
+  (`dst X, dst Y, w, h` per rectangle), not a 256 grid. The "~15 % variants" were
+  a wrong model.
+- **LSTA**: the count was never unreliable — it counts **sprites *and* `PRMD`
+  primitives** (64/64 exact).
+- **RATC**: "one level deep" is not a limitation; nested records are **leaves
+  that reference siblings by name** (10 144/10 148 resolve).
+- **UI screens are fully reconstructible from their bundle** — element list +
+  order (declaration table, with a **parent index**) and placement/animation
+  (keyframe region). **Validated against the running game to ±2 px.**
+- **Movie ↔ subtitle ↔ voice link solved statically** (101 movies) — `INDEX` had
+  it filed as needing the running game.
+- **XPR2 channel order confirmed** against the game (hue 23.3° vs 9.3°).
+
+### Meshes — the user-reported viewer bug
+- Root-caused, **after one wrong turn I corrected in place**: the giant slab on
+  `e106` is not a stray volume but an **XBG7 mis-decode** — the same resource is a
+  49×23×42 turret in 11 containers and 1600×2100×4800 in 3.
+- **New detector**: a resource shared across containers must decode to the same
+  bounds. **125 of 681** shared resources fail that check — a measured lower
+  bound on *silent* mis-decodes (distinct from the 814 honest declines).
+
+## Two disc defects found
+`SUBTITLE_S12B.tbl` (referenced by the movie table, present in **no** language)
+and `pmbase.t32` (placed by `pmbase.rat`, present **nowhere**). A reimplementation
+should skip a missing asset rather than treat it as a decode failure.
+
+## Process notes worth keeping
+- Several "the data is inconsistent" comments meant **our model was incomplete**
+  (T8aD variants, the LSTA count). Re-test such notes rather than routing around
+  them.
+- A test that walks the *oracle's* items and looks each up in our output **can
+  only fail one way** — it never sees extras. That shape hid the ship bug and,
+  earlier, `include_external`.
+- When a diagnosis has eliminated every hypothesis and the last step is *a
+  visual*, do the visual first. Three iterations went by before a 30-second
+  render showed it.