fix(strategy27): retain compound candidate history through recovery - #288

Compound high/low markers disappeared when their feed changed epoch, returned a stale cursor or became unavailable: the compound client cleared both its protocol state and its verified display history. Strategy27 0.6.2 resets protocol validation separately, preserves immutable candidate IDs and the eviction cutoff, and merges recovery snapshots without deleting absent candidates or recreating cleared observations.

Terminal protocol, drawing and repair failures now stop polling and suspend unfinished presentation while preserving verified history with reconnect guidance. Age pruning, manual clear and context retirement still remove owned entities; late creations cannot revive cleared or suspended records. Sequence, hash, symbol and retention limits remain enforced.

Validation:

• Strategy27 suite: 180 tests passed, including source and generated-entrypoint coverage of unchanged paired entity IDs and positions across epoch changes, stale cursors, bootstrap replay and 503 recovery.
• Full repository suite: 962 tests passed.
• Affected build, all Binance userscript syntax checks, release metadata/source contract and git diff whitespace check passed.
• Isolated browser panel preview passed for high/low candidates, bounded history, collapse and both languages; screenshots inspected.
• The live Binance one-second chart and both connections were inspected before publication. No real compound sample was present during that observation, so live candidate-retention acceptance remains unverified.