Connect genuine Ix expansion setup to playable prototypes

Add an offline Ix initializer through the real setup pipeline, supporting Basic
and Advanced play, base factions, Ixians and Tleilaxu with the full 47-card deck
and 22-card spice deck. Preserve all normal start and publication gates.

Add a reusable local prototype starter: back up the named fresh ready lobby,
initialize it once by exact version/state comparison and preserve seat/recovery
tables and other rooms. Update the existing checklist with a separate prototype
stage and document functional scope, source interpretations and later refinement.

Six new tests cover all-profile private setup, exact typed starting forces,
Face Dancer/treachery custody, JSON continuation, two fixed-seed complete games
and local SQLite write/rejection boundaries. Independent review caught a missing
JSON version update, now fixed and covered; focused checking fixed one test typing
error before the stable broad check. No new rule interpretation was introduced.

Validation: types, lint and 4,211 offline tests passed (123.237s); production build
passed (6.543s); all 40 HTTP tests passed (23.578s). Source-bound report:
20260913-ix-prototype-final/report.json, fingerprint
3b8f295593bcb314bb72308d81739006b11d949d1e5906dbf6ce0704b15ebd72.

Browser W5LE6VFB: human Ixian + Medium Tleilaxu + Hard Atreides from genuine
setup, private starting-card refresh, Weather Control, mobile stronghold placement,
then owned Brutal autopilot. Atreides won on turn 1; this short complete journey
is not proof of every card or faction interaction. Finished private hand restored
at phone width; expanded Poison Tooth was readable. Fixed-seed offline games
2026091301 (Basic) and 2026091302 (Advanced) both completed with both Ix factions.

All 64 opening room versions/hashes are unchanged. One browser room and 30 HTTP
rooms were added, totaling 95. Reused the running server; no restart or automation.

Aggregate goal counters: 59,524,858 to 59,976,567 at completed verification,
451,709 tokens before final Git overhead. Two bounded workhorse helpers handled
inventory/tests and independent review; one stable full check/build/HTTP run.
Full game scope remains active and unfinished; future work prioritizes missing
functional prototypes before exhaustive refinement and final acceptance.

docs/IX_PROTOTYPE.md

@@ -0,0 +1,72 @@
+# Ixians & Tleilaxu functional prototype
+
+13 September 2026. This connects the existing expansion mechanics to genuine
+setup and an ordinary saved browser table. It is a **working prototype**, with
+rules coverage still partial. Normal Advanced/expansion start gates and the
+publication gate remain closed.
+
+## Playable boundary
+
+`initializeIxGameForAudit` uses the same staged setup as the game: prediction,
+private traitors, starting forces, private Ixian starting-card selection, then
+the automatic deal and first Storm. It accepts Basic or Advanced, two through
+six ready players, base factions plus Ixians and Tleilaxu, and exactly the Ix
+expansion. It includes the 47 physical Treachery Cards and the 22-card Spice
+Deck containing Sandtrout from the outset. It does not inject cards or change
+factions after setup. Tech Tokens, Stronghold Cards, Homeworlds, Nexus Cards and
+combined expansion decks remain separate integration work.
+
+The actual player controls, private views, bot actions and saved game format
+are reused. The initializer cannot redeal a started or nonempty game, and no
+player action or HTTP endpoint dispatches it. Existing card outcomes and the
+interpretations documented in the [Ix deck](../game/reference.ts),
+[component inventory](COMPONENT_INVENTORY.md), [Ixian Cunning sources](NEXUS_IXIAN_CUNNING_RULES.md)
+and [setup contract](ADVANCED_SETUP_TEST_SEAM.md) are preserved. In particular,
+the Thumper/Sandtrout timing, repeated Harvester effects and remaining faction
+interactions are not settled by this prototype.
+
+## Start a local prototype table
+
+Create a **new** local browser room with the Ixians & Tleilaxu expansion selected,
+choose its human/AI factions, and mark everyone ready. Retain its room cookie.
+Use the current database version of that named lobby with:
+
+```sh
+node --import tsx tools/start-prototype.ts \
+  --db PATH_TO_LOCAL_D1_SQLITE \
+  --room EIGHT_CHARACTER_CODE \
+  --version CURRENT_LOBBY_VERSION \
+  --out /private/new-prototype-checkpoint
+```
+
+The output directory must be new and outside the repository. The command first
+captures an online backup and saved-room hashes, then initializes only that
+fresh ready Ix lobby. An atomic version-and-state comparison rejects a concurrent
+lobby change. It leaves every seat/recovery record and other room untouched.
+Its private result records the source revision/fingerprint and before/after
+versions. Refresh the invitation to continue through normal private setup.
+Keep the resulting game; rerunning setup on it is rejected. Reuse the running
+server—this workflow does not require a restart.
+
+## Evidence and remaining work
+
+`tests/ix-prototype.test.ts` exercises genuine Basic/Advanced setup at all four
+AI profiles, private Ixian choices, Face Dancer custody, starting hands and
+JSON restoration. Two complete mixed-profile games include both expansion
+factions, checking final force/card inventory and winners. These sample games
+do not prove every card was played or measure difficulty ordering.
+
+`tests/prototype-room.test.ts` covers the local saved-room entry, unchanged
+sessions/other rooms, stale version and redeal rejection, and invalid lobby
+immutability. Independent review caught and fixed a missing JSON version update
+in the prototype writer; the database row and saved game now advance together.
+It uses in-memory SQLite. Browser room `W5LE6VFB` was created normally with a
+human Ixian, Medium Tleilaxu and Hard Atreides. It reached private traitor and
+starting-card choices through real setup, restored the same card offer after
+refresh, played Weather Control, placed the mobile stronghold at Sihaya Ridge 9
+and handed the owned seat to Brutal autopilot. No post-setup card/force staging
+was used. Its later outcome and final checks are recorded with the checkpoint.
+The earlier writer's version mismatch was corrected by the first ordinary
+game action; current browser state and database version were confirmed equal.
+Expand combination and rules coverage during
+the later refinement pass; continue prototyping independent missing functions.