Add fixed core HUD and shared service window for T5 and T6

README.md

@@ -359,16 +359,87 @@ For this upgrade also verify stale URL settings are ignored, an empty `.b`
 shows zero, `.w all` reports insufficient balance, and an EC rebuild/removal
 settles legacy and public journals without duplicate ledger entries or lost points.
 
+## Core HUD and service window (T5 and T6)
+
+The HUD uses a fixed upper-right panel below the top edge, leaving room above
+for performance overlays and below for stock player scores, ammo and equipment.
+The header contains `TWS ZOMBIES` and `discord.tws.lol`; match and round timers
+share the next row. Zombie count and current/maximum HP sit above a full-width
+health bar. HP numbers remain visible at full health. A reserved footer holds
+the AFK indicator; the former co-op player-name row is removed.
+
+The core is created once per connection and stays in place when services open,
+across death and respawn, and while newcomers spectate. Unavailable values use
+placeholders until the first-spawn callback binds the data displays. Creating the
+panel does not start the match clock. Each engine retains its timer behavior;
+clocks, health and zombie-count displays freeze at game over. Health display
+fallbacks never modify gameplay max health.
+
+Common owns one fixed-height service window directly below the core. `.help`
+and its `.commands` alias show four commands per page, with command and
+description columns plus a page count. Pages advance automatically every
+12 seconds and close after the last page. Repeating either command restarts
+page one. The order is `.help`, `.afk`, `.back`, `.join`, `.leaders`, `.b`, `.d`,
+`.w`, omitting commands whose modules are not registered. The `.join` description
+continues to identify its newcomer restriction.
+
+Records use the same service window. Help pauses a visible record and resumes
+its remaining page time when help ends. `.leaders` during help replaces the
+pending record with a fresh replay from page one. One service is visible at a
+time, and neither changes the core's position or height. Services are private
+to the requesting player and work when the HUD module is omitted.
+
+Install HUD `1.2.0`, leaderboard `1.1.0` and AFK `1.0.1` with the matching
+game's common `1.2.0+`; update the installed scripts together and restart the map.
+There is no new native-plugin or backend requirement, and this change does not
+require a full server-process restart. Existing leaderboard plugin requirements
+still apply. Unchanged modules retain their existing common helper interfaces.
+
+### HUD validation
+
+Run `node tools/check_hud.mjs` for portable pagination, service arbitration,
+request replacement and cleanup checks, and `node tools/check_leaderboard.mjs`
+for record data handling. Run `node tools/check_bank.mjs`,
+`node tools/check_join.mjs` and `node tools/check_telemetry.mjs` for unchanged
+command/lifecycle regressions. These
+checks use engine shims and do not prove GSC VM behavior. Follow the
+[T6 compiler instructions](t6/scripts/README.md#validation); T5 requires a live
+Plutonium server because gsc-tool has no T5 backend.
+
+Before rollout, validate both engines in Plutonium:
+
+1. Check 16:9 and narrower/wider resolutions, safe-area settings, long match
+   timers, stock map inventory/objectives, performance overlays, player scores,
+   ammo and interaction prompts. The core and service panels must stay clear of
+   these areas and retain their geometry for every page.
+2. Join before spawning, join mid-match, die/respawn and reconnect. Verify one
+   core per player, spectator placeholders, no early match-clock start, correct
+   health/Juggernog changes, and frozen timers at game over. Toggle AFK and back
+   without overlapping the health bar or changing existing protection behavior.
+3. Open `.help`, `.HELP` and `.commands` with all modules installed. Verify two
+   pages of four commands, 12 seconds per page and automatic dismissal. Repeat
+   on page two to return to page one. Remove optional modules and restart the
+   map to confirm filtered pages, then restore them.
+4. Interrupt records with help and check that the interrupted page resumes for
+   its remaining time. Repeat `.leaders` while help is open; only the latest
+   replay should start, at page one. Check long holder names, ties spanning
+   pages, no records, and unavailable records. Repeat without the HUD installed.
+5. Disconnect or end the game while help/records are active, reconnect and
+   request them again. Verify no duplicate elements, stale timeout closures or
+   surviving service windows. Confirm `.join`, bank commands and lobby lock
+   retain their existing behavior with their required modules installed.
+
 ## Map record announcements
 
 Install `tws_t5_leaderboard.gsc` for T5 or `tws_t6_leaderboard.gsc` for T6,
-**along with the updated common module** for that game.
-The new module privately announces the current map's fleet-wide highest recorded
+**along with common `1.2.0+`** for that game when using leaderboard `1.1.0`.
+The module privately announces the current map's fleet-wide highest recorded
 round and every tied holder once per connection, including spectator newcomers.
 Type `.leaders` to replay the record privately from the latest usable cache.
 Repeating the command restarts the announcement from its first page. It appears
 in `.help` when the leaderboard module is enabled. If no usable record is
-available, the command asks you to try again shortly.
+available, the service window identifies the record as unavailable and keeps
+the `.leaders` retry reminder; this differs from a valid empty record history.
 It reads Electric Cherry's public `/api/leaderboard` endpoint without a token;
 only completed matches contribute. Ties may come from the same run or separate
 runs. Names are the API's latest player names, with players identified by GUID.
@@ -390,13 +461,17 @@ exist in the API's map list and match the current game and engine map. Clear it
 when changing variants; restart the map after changing these settings.
 
 The announcement starts five seconds after player readiness and waits for the
-initial record fetch if necessary. It appears in the same HUD area as `.help`,
-below the health bar, with a heading such as `Record: Round 23` and holder names
-underneath. Each page shows up to three holder lines for 12 seconds. Opening
-`.help` hides the record and pauses its display time until help closes.
-All holders are included; colour/control codes are removed, and unusually long
-names are shortened to keep messages readable. HUD elements are removed when
-the announcement finishes, the player disconnects, or the game ends.
+initial record fetch if necessary. It appears in the common-owned service
+window beneath the core, with a `MAP RECORD` heading, prominent round value,
+holder names, page count and `.leaders` replay hint. Each page shows up to three
+holder lines for 12 seconds. Opening `.help` pauses the record's remaining
+page time until help closes. A `.leaders` request during help replaces any
+pending replay and starts from page one after help closes.
+All holders are included; colour/control codes are removed, and overlong
+individual names are abbreviated without splitting UTF-8 characters. Bounded
+lines and additional pages preserve every tied holder. The window hides when the
+announcement finishes and its elements are reused for subsequent services.
+Disconnect or game end cleans up service elements.
 
 One level worker fetches the map list and pages of three players, stopping when
 the highest-round tie ends. Successful snapshots refresh every five minutes.