Rebase MISTER EXO's ida-codemode port onto the current tree

Mechanical part of the port: the 27-file patch was cut against a base ~148
commits behind us, so it did not apply. Resolved 11 conflicts (all of them
diff drift, not semantic clashes) and the three file deletions:

- app.py: the patch re-inserted _do_rename/_do_name_addr/_seek_split etc. as
  "theirs" because our tree moved them to edit_ctl.py/trace_ctl.py. Kept ours
  and applied the real intent (WorkerClient->CodeModeClient, .call->.invoke,
  _open_worker_client->_open_database_client) at their current homes.
- domain.py: kept Head as a NamedTuple -- the patch reverted it to a frozen
  dataclass, which the perf work measured at 2.9us vs 1.9us per row on a
  quarter-million-row walk. Dropped _fetch_output (no download_url under Code
  Mode) and its now-dead urllib/json imports.
- pane.py: the patch's deletion swallowed our zellij support along with the
  worker-reaping block it meant to remove. Kept zellij, removed the reaping.
- test_scenarios.py: the idb_save->save_database teardown hunk belongs to
  tests/_fixtures.py in our tree; applied it there and kept our pc_num_format
  scenario that the drift landed on.

Three defects in the patch itself, fixed here:

- It made "import idatui" hard-require ida_codemode, so every offline suite
  died at import -- including the pure ones (graph/index/trace) that are the
  house rule for "tests/run.py --fast". The import is now deferred and gated
  on the binding, which is also what lets the port's own contract tests
  inject a fake DatabaseHandle.
- project.stage() inlined an ida_codemode.registry import and treated "library
  not installed" as "someone owns this database", which broke IDA-free project
  staging. Ownership lookup moved to codemode_client.database_owner().
- tests/test_codemode_client.py had no NEEDS_IDA marker, which tests/run.py
  rejects outright.

Offline suite: 301 passed, 0 failed. Against master's 344 the whole delta is
accounted for: -40 worker_client (module deleted), -18 launch sweep checks
(behaviour deliberately removed) +3 guarding that it stays removed, +2 pool
(GUI-save semantics), +13 new codemode_client contract tests.

NOT yet done, and the port is not functional without it: the adapter is
missing five operations our tree grew since the patch's base (flowchart,
op_format, pc_nums, pc_num_format, survey_binary) and its "heads" predates
back-walking and digest/expect.

1 files changed, 6 insertions, 6 deletions

diff --git a/docs/SPLIT_VIEW.md b/docs/SPLIT_VIEW.md
index de37dc1..c421656 100644
--- a/docs/SPLIT_VIEW.md
+++ b/docs/SPLIT_VIEW.md
@@ -29,11 +29,11 @@ Ghidra highlights **all** instructions a C line owns. We have one ea per line
 (the marker), not the set. Getting the set is the only real work, and it's a
 known technique:
 
-ida-pro-mcp derives the per-line marker via
+The old ida-pro-mcp backend derived the per-line marker via
 `cfunc.get_line_item(line, col=0, …).get_ea()`. To get the **full set**, sweep
 every column of the line (`get_line_item(line, x, …).get_ea()` for `x` in
-`0..len`) and collect distinct non-`BADADDR` EAs. Same proven API, swept across
-the line. A custom `decomp_map(ea)` tool in `server/patch_server.py` returns
+`0..len`) and collect distinct non-`BADADDR` EAs. The Code Mode adapter's
+`decomp_map(ea)` operation returns
 `[{line, primary_ea, eas:[…]}, …]`; invert for `ea → line`.
 
 ## State model
@@ -78,14 +78,14 @@ decomp→listing uses `ListingModel.ensure_ea`. Tab re-links from the new driver
 Still single-ea per line (one instruction highlighted); the region comes in
 phase 3.
 
-**Phase 3 — rich highlight. DONE.** `decomp_map` custom tool
-(`server/patch_server.py`) sweeps `cfunc.get_line_item` across every column of
+**Phase 3 — rich highlight. DONE.** The Code Mode `decomp_map` operation
+(`idatui/codemode_client.py`) sweeps `cfunc.get_line_item` across every column of
 each pseudocode line and collects the EAs from each item's `dstr()` (`'EA: desc'`
 — the same source as the `/*ea*/` marker, so it aligns). `Program.decomp_map(ea)`
 returns the per-line ea lists (cached by name-gen); the app loads it async into
 `_split_eamap` / `_split_ea2line` and `_sync_split` bands the **whole** instruction
 region of a C line (and uses the exact ea→line inverse for the reverse). Falls
-back to the single marker until the map lands. Verified on the pilot's real worker
+back to the single marker until the map lands. Verified on a real Code Mode database
 (alignment + multi-instruction region band).
 
 **Phase 4 — polish. DONE.**