v2.6.0 — Two-phase ingest, /haze suggest, preload header

Driven by a real 4hr Cursor session that ingested 31 transcripts → 6 concepts and surfaced three friction points addressed here.

Features:
- Two-phase /haze ingest --new — Phase 1 summarizes each transcript to wiki/sessions/<id>.md; Phase 2 extracts concepts from summaries. Drops Phase 2 token cost ~10x. New flags: --summarize-only, --synthesize-only.
- /haze suggest [--top N] [--refresh] — concept discovery via frequency + cross-source analysis with NEW/STALE/EXISTING buckets. Read-only until user approves.
- Preload header — session-start hook prints HAZE PRELOAD block listing what got injected.
- Manifest schema extended with summarized_at + concepts_extracted_at (backward compat with pre-v2.6 entries).

Carryover from v2.5: cursor-install.sh, Cursor port templates, hooks.json version=1 fix, rotating debug log.

See README "Release History" for the per-version log.