fix(humanize): repair grounding and per-user thread state

[yunhai89]

Summary

• Repair grounding assembly and injection so Planner receives structured grounding before memory lookup, with memory scoped by threadUserIds.
• Resolve quoted messages outside the rolling window through getReply / get_msg / history and store them as lightweight replySource context.
• Make correction timeouts and strong-signal chase limits per-user, so one member's correction does not silence the whole group.
• Keep shadow and real replies consistent, and advance the cursor when cooldown or rate limiting skips a message.
• Expose webSearch through the assembled runtime and fix the stress-test import path.

Root cause

• groundingObj was referenced before declaration, so the resulting TDZ error was caught and silently disabled grounded memory.
• Planner grounding injection returned the wrong shape.
• Correction handling referenced getGroundingRaw outside its build closure and used group-global timers/streaks.
• Quote resolution only searched the in-memory rolling buffer.
• Shadow replies did not update the strong-reply streak, allowing inconsistent chase behavior.

Validation

• node scripts/run-tests.mjs: 32/32 module files passed, 0 failures
• node stress/anti-misread/deterministic.mjs: 61/61 passed
• node stress/grounding-test.mjs: 9/9 passed
• ESLint passed for all changed files
• git diff --check passed

Note

A full-repository eslint . still reports the pre-existing unrelated model/selfstate/reflection.js:87 undefined budget issue; this PR does not modify that file.