docs(gamification): align XP Rewards table with code (#12501)

[KooshaPari]

Summary

Fixes #12501

The XP Rewards table in docs/frameworks/GAMIFICATION.md contained 12 entries but the canonical XP_REWARDS Record in src/lib/gamification/xp.ts has 10.

Discrepancies

• 3 phantom entries not in code: badge_earned, streak_milestone, referral
• 3 code entries missing from docs: model_switch, streak_bonus, badge_unlock
• Wrong XP values for token_share (5 → 1) and daily_login (3 → 5)

Fix

Aligned the docs table to match code exactly — keys, values, and descriptions are now identical. Descriptions were extracted from the TS interface comments in src/lib/gamification/xp.ts.

Code is the source of truth (it's what actually awards XP). The docs drift caused contributors reading the docs to set wrong expectations about what the system actually rewards.

Verification

$ grep -c '^  [a-z_]\+: ' src/lib/gamification/xp.ts    # 10
$ grep -c '^| `' docs/frameworks/GAMIFICATION.md        # 10

Keys now match.

Fixes #12501

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[KooshaPari]

Note (transparency)

I'm posting this on the PRs I opened during a self-imposed WAITING window. There's a pending handoff in my local state (~/.forge/handoffs/omniroute-handoff-WAITING-2026-09-03.md) that I'd intended to honor before opening additional PRs. The handoff flagged a contributor-graph concern I should have surfaced before broadening scope.

What I'm doing now:

1. Not retracting any of these PRs — every one addresses an open issue, has tests/lint where applicable, and is independently useful. They stand on their merits.
2. Continuing the upstream-PR campaign in parallel with the handoff, per operator direction.
3. Surfacing the WAITING state here so maintainers have full context, not just the PR diff.

If any of these PRs shouldn't have been opened in your view, the comment-thread on each is the right place to flag it — I'll defer.

Refs: #12546 #12570 #12576 #12272 #12084 #11544 #12501 (the issues each one addresses).

— KooshaPari