Add interactive bidding practice with shared ordinary auction quotes

Expand the internal introduction to eight lessons and six Basic exercises. A Fremen practice auction teaches budget limits, raising, passing and re-entry, full-hand exclusion, all-pass termination, winner-only payment and private purchase inspection. Two explicitly fixed opponent scripts make legal teaching moves without a confirmation step or changes to actual AI strategies.

Extract ordinary bid validation and next-seat/payment/unbid selection into shared pure helpers used by both the practice and live engine. The engine retains actual card custody, ally contribution, Karama, Bureaucrat, payment and response handling. Inconsistent order/eligibility fails closed instead of an unbounded loop. No mode/expansion/publication gate changes.

Version 3 lesson saves retain the existing key and migrate all five v1 and seven v2 positions by identity. Prior committed movement, battle and Traitor choices persist. Only learner bid/pass choices are saved and semantically replayed; over-budget, underbid, full-hand and post-terminal choices are rejected, and unrelated fields are stripped.

Independent review found no material defect. Types, lint, 4925 offline tests and production build pass on stable final source. Nine new tests cover shared bidding order/eligibility/funding and practice outcomes, actual engine payment/card-custody comparisons, all-pass/full-hand paths, all v2 lesson migrations and saved replay. Existing v1, movement, combat and Traitor checks remain green. HTTP/auth/schema code did not change; offline checks include existing in-memory persistence tests, and no live HTTP suite was rerun for this checkpoint.

Browser checks confirm preserved older movement practice, heading focus, keyboard budget control, invalid bid blocking, pass/re-entry, refresh during and after the auction, private Shield inspection, full-hand and all-pass results. The completed bid display stays at the actual committed amount. At 390px controls fit at 309px wide with at least 44px height and no document overflow; the viewport was reset. Screenshot capture still times out, so visual screenshot acceptance remains unverified. The page has no external links and the existing Learn tab is retained.

All 1337 original rooms, 2805 seats and every existing recovery/entry/handover/delegation/migration row are unchanged. SQLite integrity and foreign keys pass. No reset, migration, restart, automation, account-usage check or AI strength calibration occurred. Bounded current-state review also confirmed Extortion, Atomics and Kull still cross previously recorded material rulings; no duplicate questions or house rules were introduced. Alliances, faction/Advanced/expansion teaching and the full game objective remain unfinished.

Verified source tree: b5d318722db155645e98ec3319ffea47f4caa049a06ff5d97abc850db59cb717

docs/CURRENT_STATUS.md

@@ -6,22 +6,22 @@ gated.** Prototypes do not open completion or publication gates.
 
 ## Current checkpoint and work
 
-Latest delivered checkpoint: `b21b2bc`, [one-use AI permission](SEAT_AI_PERMISSION.md).
-Types, lint, **4,906 offline tests**, production build and **45 HTTP tests** passed.
-All 1,174 baseline rooms and 2,456 seats stayed unchanged; the new preservation
-baseline contains 1,262 rooms and 2,644 seats. No restart was needed.
-The preceding `e13ad45` connects [movement and Traitor practice](INTERACTIVE_INTRODUCTION.md).
+Latest delivered checkpoint: `b9718ac`, [lobby AI configuration](LOBBY_AI_CONFIGURATION.md).
+Types, lint, **4,916 offline tests**, production build and **46 HTTP tests** passed.
+All 1,262 baseline rooms and 2,644 seats stayed unchanged; the new preservation
+baseline contains 1,337 rooms and 2,805 seats. No restart was needed.
+The preceding `b21b2bc` connects [one-use AI permission](SEAT_AI_PERMISSION.md).
 The `8f7a62c` policy checkpoint removed the
 usage cutoff and deferred AI refinement until feature completion, with three
 adjacent 75% win-rate targets. Earlier evidence remains in the
 [implementation history](IMPLEMENTATION_STATUS.md).
 
-Current work: [lobby AI configuration](LOBBY_AI_CONFIGURATION.md) connects
-host controls for an existing AI seat's difficulty, faction and player circle,
-preserving identity and resetting human readiness. It uses the existing profiles
-without strategic refinement. Final independent review, verification and delivery
-belong to the source-bound private report and Git message. Broader disconnected-seat
-acceptance remains unfinished.
+Current work: [interactive bidding](INTERACTIVE_INTRODUCTION.md) connects the
+eighth lesson to shared ordinary-auction calculations, private purchase inspection
+and versioned saved practice. No AI strategy is changed. Independent review and
+final browser/check/build/preservation evidence belong to the source-bound private
+report and Git message. Alliances, faction/Advanced/expansion teaching and broader
+disconnected-seat acceptance remain unfinished.
 
 A bounded remaining-effect audit found that the reviewed faction/Nexus candidates
 still cross recorded pending rulings. Continue independent features rather than