fix(gfx): op 0x215 query registry is separate from the geometry store

The retained-mode "2nd CG renders off-screen" bug: GfxState conflated two
distinct native structures. It assigned a fabricated AcquireSlot() slot on
every GetOrCreate (called by all geometry/draw ops) and returned it from
QuerySlot (op 0x215). But Ghidra (gfx_op_0x215_register_query @0x42a0b0 /
gfx_op_0x1a2_registry_insert @0x42d360) shows 0x215 does map.find(handle) over
a registry populated ONLY by op 0x1a2 -- it never allocates a slot.

So a CG handle (never 0x1a2-registered) read back as "existing", took the
existing branch of label_12649, ran get-texture-size on the wrong slot (0),
got size 0, and computed dst = pos(0,0) - (w/2,h) = (-400,-600) -> off-screen.
The real engine returns -1 -> the fresh branch -> anchor from the INIT2 arrays
-> dst=(0,0).

Fix: GfxState keeps a separate _registry (HashSet) populated only by
Register() (op 0x1a2); QuerySlot returns the handle if registered else -1, and
no longer consults the geometry store or invents slots. Drop AcquireSlot /
GfxObject.Slot / the free-list.

Verified: Age.Cli gfx --boot SC0000.BIN -> all event CGs dst=(0,0), zero
(-400,-600) draws; Godot --boot pages 1/2/4 render opening CGs full-screen;
engine 44/44; sweep parity 284 exit / 13 STEP-LIMIT unchanged.

Docs: engine-re.md (query-registry-vs-geometry-store section), opcodes.toml
0x1a2/0x215 rebuilt; Ghidra helpers gfx_registry_map_find/hash_insert
annotated + saved. Tests rewritten to the native contract.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

vm-map/opcodes.toml

@@ -3457,7 +3457,7 @@ abi_source = "kelebek+decode-validated"
 [opcode.semantics]
 name = "gfx-cmd-register"
 category = "draw"
-summary = "0x1a2 (val) — gfx cmd-type 3. Handler gfx_op_0x1a2_registry_insert @0x42d360: builds key '%c%8.8x'(3, operand-desc) and INSERTS operand 1 into the gfx command-buffer registry (FUN_0042cf70, open-addressing hash). This is what POPULATES the registry that op 0x215 queries. NOT save/scene (raw Kelebek VA 0x428010 drifted to op 0x1ac save handler). See docs/engine-re.md gfx op-contract table."
+summary = "0x1a2 (handle) — gfx cmd-type 3. Handler gfx_op_0x1a2_registry_insert @0x42d360: builds key '%c%8.8x'(3, operand-desc) and INSERTS operand 1 into the op-0x215 query registry (FUN_0042cf70, open-addressing hash; native stores map[handle]=handle). This is the SOLE populator of the registry op 0x215 queries — the geometry SET/draw ops (0x217/0x219/0x1ff/0x1fb/0x202/...) do NOT register. VM impl: GfxState.Register(handle) (a separate set from the geometry object store). Conflating the two (registering on every GetOrCreate) was the retained-mode geometry bug: CG handles wrongly read back as 'existing' and collapsed to (-400,-600). NOT save/scene (raw Kelebek VA 0x428010 drifted to op 0x1ac save handler). See docs/engine-re.md gfx op-contract table."
 noop_headless = false
 source = "investigation"
 confidence = "high"
@@ -5249,7 +5249,7 @@ abi_source = "kelebek+decode-validated"
 [opcode.semantics]
 name = "query-gfx-object?"
 category = "draw"
-summary = "0x215 (out)(handle_id) — native graphics command-buffer op. Real handler FUN_0042a0b0 (Ghidra-resolved via the dispatch table ctx[0x26c93+op]; Kelebek's 0x421160 is VA-drift, lands in an unrelated fn). Does TWO things: (1) writes cmd-type 5 into the CURRENT gfx-object record `[ctx+0x53d88 + ctx[0x53d14]*0x78]` (a command-buffer registration, parallel to op 0x1a2→type 3); (2) returns `out = map.find(handle_id)` over an engine-internal associative registry (found value, else 0xffffffff=not-found), sign-tested (gre/lt 0) to drive label_12649's slot-select branch + set working slot G[0x62452]. So `out` is NATIVE COMMAND-BUFFER STATE (the registry is populated by sibling gfx ops — op 0x1a2→FUN_0042cf70 is the hash insert), NOT the VM global bank → seeding story-state CANNOT reproduce it. Stubbed → constant return → every draw collapses to slot 0 → anchor-preserve reads foreign-sized textures → the cumulative bg/sprite drift. SETTLES the drift as (b) a genuine native op, NOT (a) state-divergence. Faithful fix = model the gfx command-buffer (record array + handle→object registry) and run the gfx ops instead of stubbing — static/Frida-free (handlers now readable; inserts are bytecode-driven). Full decode + verdict: docs/engine-re.md (op 0x215 section)."
+summary = "0x215 (out)(handle_id) — native graphics command-buffer op. Real handler FUN_0042a0b0 (Ghidra-resolved via the dispatch table ctx[0x26c93+op]; Kelebek's 0x421160 is VA-drift, lands in an unrelated fn). Does TWO things: (1) writes cmd-type 5 into the CURRENT gfx-object record `[ctx+0x53d88 + ctx[0x53d14]*0x78]` (a command-buffer registration, parallel to op 0x1a2→type 3); (2) returns `out = map.find(handle_id)` over an engine-internal associative registry (found value, else 0xffffffff=not-found), sign-tested (gre/lt 0) to drive label_12649's slot-select branch + set working slot G[0x62452]. So `out` is NATIVE COMMAND-BUFFER STATE (the registry is populated by sibling gfx ops — op 0x1a2→FUN_0042cf70 is the hash insert), NOT the VM global bank → seeding story-state CANNOT reproduce it. Stubbed → constant return → every draw collapses to slot 0 → anchor-preserve reads foreign-sized textures → the cumulative bg/sprite drift. SETTLES the drift as (b) a genuine native op, NOT (a) state-divergence. Faithful fix = model the gfx command-buffer (record array + handle→object registry) and run the gfx ops instead of stubbing — static/Frida-free (handlers now readable; inserts are bytecode-driven). Full decode + verdict: docs/engine-re.md (op 0x215 section). RETAINED-MODE FIX (2026-07-07): the registry MUST be separate from the geometry object store — it is populated ONLY by op 0x1a2, never by the geometry SET/draw ops. VM: QuerySlot returns the registered value (=handle) or -1, NOT a fabricated per-object slot. CG handles are never 0x1a2-registered → query returns -1 → label_12649 takes its FRESH branch (anchor from the INIT2 arrays) → dst=(0,0). The prior GfxState.GetOrCreate-assigns-AcquireSlot model made CG handles read as 'existing' → existing branch called get-texture-size on the wrong slot (0) → dst=(-400,-600) off-screen (the '2nd CG off-screen' bug)."
 noop_headless = false
 source = "investigation"
 confidence = "high"