docs(wasm): E9 static analysis - found UNWINDING/DONE_FLAG bug; reframe root cause to register-value codegen

docs/wasm-inflate-panic.md

@@ -204,6 +204,41 @@ remaining paths are generated-wasm inspection of the BLOCK_PTR/register restart
 sequence, or building per-op TCI. A deterministic reproducer exists (remove
 `wasm_tci_only_tb`, open example.txt, faults at MEPC 0x4201e210, gen 16).
 
+### E9 — static analysis of generated wasm (dump + wasm2wat)
+Added a node-only dump hook (`wasm_dump_module`, tcg.c finalize) that writes the
+first compiled store-TB and load-TB modules; `_scratch/dump-tbs.mjs` boots the
+firmware under node far enough to emit them. `wasm2wat --enable-threads` gives
+readable IR.
+
+**Finding 1 (real bug, fixed-then-shelved):** the ld/st slow paths detect an
+asyncify yield with the thread-global `DONE_FLAG` (ctx+20), while the general
+call path uses `UNWINDING` (ctx+28), which is reset before each call and set
+*only* by the coroutine switch. `DONE_FLAG` is set by *any* nested ld/st helper,
+so a nested guest access inside a store/load helper that then yields makes the
+outer op falsely read "completed" and swallow the unwind. Converting ld/st to
+the `UNWINDING` mechanism is the correct fix. **But** rebuilding with compiled
+stores + the UNWINDING fix still crashes identically (gen 16, same MEPC), so the
+store helpers on this path never actually yield — this bug is latent here. Change
+shelved (not shipped) to avoid touching the working compiled-load path without a
+green test; recorded for a future upstream fix.
+
+**Finding 2 (reframes the root cause):** combine E5 with the load result. E5
+routes *every* store through the C softmmu helper (correct memory write) and
+still crashes; loads share the identical restart/block structure and work. So
+the corruption is **not** in the store data codegen, the restart machinery, or
+the yield handling. What remains is that a store *writes* guest memory using an
+address/value taken from guest registers (wasm globals). A compiled TB that
+computes a wrong register value corrupts memory only through a store — a wrong
+address fed to a *load* just reads harmless garbage. This matches every prior
+result: emergent (depends which ops precede a store), deterministic, and
+non-localizable by store region or width. The remaining hunt is a
+register-producing op whose compiled codegen diverges from TCI, exposed
+destructively via stores — which needs a compiled-vs-TCI per-TB register
+differential, not more whole-TB gating.
+
+Tooling retained: `wasm_dump_module` + `wasm_tb_had_store/load` tags +
+`_scratch/dump-tbs.mjs`.
+
 ### Next options
 1. **Ship E1 as a guarded workaround** — reader works now; measure real
    navigation/page-turn perf before judging it unacceptable.