Allow Ecaz Ambassadors on the placed mobile stronghold

Share dynamic stronghold legality across placement, cancellation, bots and controls. Keep the HMS sheltered, preserve original fees and entry effects, and display its public Ambassador attached to the stronghold interior.

Cover genuine Basic/Advanced placement, paid movement entry, card continuations, prevention and native relocation. No Terror or direct-shipment permission is added.

docs/ECAZ_AMBASSADORS_RULES.md

@@ -2,6 +2,93 @@
 
 Audit: 2026-09-06. Scope: ambassador inventory, setup, placement, triggering, effects, and necessary continuation boundaries. This is a developer audit, not complete Ecaz support. Only this document was written.
 
+## Placed Hidden Mobile Stronghold — 24 October 2026
+
+The source permission now composes with the actual placed HMS in Basic and
+Advanced. Publisher E3 physical p7 permits placement in any stronghold without
+an Ambassador outside storm; the authorized revised source's physical p30,A
+uses the same placement language. Publisher E1 p9 identifies the HMS as a
+stronghold and protects it from storms and worms. E3 p5 expressly excludes
+Terror from the HMS but supplies no corresponding Ambassador exclusion.
+[Official E3](https://www.gf9games.com/dune/wp-content/uploads/EcazMoritani-Rulebook-LOWRES.pdf),
+[official E1](https://www.gf9games.com/dunegame/wp-content/uploads/2020/09/IxianAndTleilaxuRulebook.pdf).
+
+This is composition of those general permissions and intrinsic shelter, not a
+new designer-specific HMS/Ambassador ruling. A bounded fresh official-index
+search reproduced these passages; direct E3 PDF retrieval returned403. The
+user-supplied revised page is used under its already recorded source authority,
+without republishing it. No priority, price, faction admission or optional-module
+ruling follows from this change.
+
+A legitimately placed HMS with a printed non-stronghold pointer is eligible,
+even when that pointing sector is in storm. An absent/malformed pointer cannot
+create a location. Placement does not require Ecaz forces or Ixian control of
+the stronghold. Preserve one token per stronghold, the original supply and
+increasing1/2/3 fees, original placement opportunity and Karama cancellation.
+Other dynamic territories do not inherit this permission automatically.
+
+The token belongs to the HMS interior, not its pointing territory. Existing
+entry exclusions and effect choices apply to an actual entry. Leaving it hidden
+keeps it attached when Ix moves the HMS; movement does not place or charge it
+again. Direct shipment by other factions remains prohibited under E1; this
+change supplies no transport permission. Moritani Terror remains excluded.
+
+The focused implementation uses one shared location/placement quote for the
+engine, available-control projection and cancellation. HMS-origin card discard
+continuations use that same real stronghold location. Public board markers and
+inspectors identify the attached face; no private event or hand is displayed.
+Complete modes, broader child/optional combinations and final assurance remain
+open; the checkpoint and verification section below records bounded evidence.
+
+### HMS implementation and proof
+
+The focused helper is `game/ecaz-ambassador-placement.ts`; engine projection,
+placement cancellation and minimal bots consume its eligible destinations.
+`EcazPlacementChoice` supplies actual paid/finish callbacks and busy guards.
+`AmbassadorBoardMarkers` places public face-up identities on printed strongholds
+or the HMS interior; full table rendering includes that layer. The shared
+fresh-discard location validator admits actual HMS CHOAM/Ix parents without
+changing event, token, beneficiary, effect or original entrant continuation.
+
+The source fixture uses actual public Ecaz/Ix/Guild setup and private Traitor
+choices. It selects only three original unopened Treachery positions, the
+native Ix private choice, nine original Ecaz packet scalars and four unopened
+ordinary Spice positions. Native Storm, forces, HMS placement and phases run
+normally:46 Basic or50 Advanced source actions before paid placement. No played
+clock, army, alliance, token or pending receipt is installed. Guild pays for
+one force at the pointer, then legally moves into HMS sector0; the Emperor
+trigger gains its printed5 bank spice. The alternate branch declines and both
+resume the original entrant. A separate original held Ix Karama prevents
+placement before payment; native next-Storm movement keeps an untriggered
+Ambassador attached. Basic CHOAM/Ix exercise their actual card continuations.
+
+Frozen proof passes **12 affected offline files135/135**, types/lint and
+production build. Twelve actual placement-control/gameplay/GameTable SSR
+journeys cover both modes, storm-point shelter, cancellation and relocation,
+plus Basic CHOAM/Ix. Eight existing-profile own-view continuations accept eight
+legal proposals, with no strategy refinement or difficulty calibration.
+Bounded independent source/continuation review found no concrete blocker.
+The first real46-action source reproduced the old static-stronghold rejection.
+Feedback fixed missing fixture expansion flags, absent optional-field assertions,
+an invalid Imperial Basin pointer and seven floating test registrations;
+no rule was loosened to accommodate a fixture.
+
+Private evidence:
+`/home/quintine/.local/share/dune/checkpoints/20261024-ecaz-hms-ambassador/`,
+including `frozen-integrated-2/report.json`, `runtime-smoke.json` and HTML.
+Verified base `659e2a4a9a8443785372d652133cdc4a11aca969`, source tree
+`09336c7c223d21b46f32cc625df3a8d4ffd362df8c2664d3aa29d540317bdcce`
+(2686 nonignored files, identical before/after checks). Only checkpoint prose,
+reference strings and evidence paths follow that proof; delivery records the
+reviewed overlay and pushed revision separately. The user PDF stays untracked.
+
+Framework aliases and CSS stubs mean this is control callback/gameplay/SSR
+proof, not browser visual or deployed acceptance. Other effects/copies,
+optional modules and wider HMS combinations need their own integration proof;
+complete modes, comprehensive rules/recovery/privacy/custody assurance and
+final deployed acceptance remain unfinished. No Terror/transport permission,
+server operation, saved-game/D1/reset/restart or deployment occurs here.
+
 ## Primary evidence and precedence
 
 - **E3:** [GF9 Ecaz & Moritani rulebook](https://www.gf9games.com/dune/wp-content/uploads/EcazMoritani-Rulebook-LOWRES.pdf), printed p.4 components; pp.7–8 Ecaz; p.9 Duke Vidal; p.15 built-in Ecaz FAQ; p.16 Karama table. Targeted searches retrieved the publisher's indexed text.