Docs: align live agent/client guidance with the v1.2 contract

[onlyxItachi]

Current main (e00854c) is released as v1.2.0, declares Python >=3.10, and exposes seven MCP tools, but several live guidance surfaces still describe the older contract:

• CLAUDE.md:55 says v1.2.0 is "pre-release, in review".
• CLAUDE.md:115 says Python 3.11+, conflicting with pyproject.toml:6 and the 3.10 CI floor.
• docs/clients.md:37-39 tells users to confirm only three digest tools plus the two capture-advisory tools.
• src/perfdigest/server/tools.py:3-7 likewise omits summarize_report and compare_metrics from its tier-1 overview.
• CLAUDE.md:3-5 calls docs/INIT_PROMPT.md canonical, while that intentionally frozen kickoff spec still locks Python 3.11+ (:54) and three tools (:117-130).

This can make agents and integration reviewers validate the wrong release state, runtime floor, and MCP surface.

Suggested scope: keep INIT_PROMPT.md frozen if that convention remains intentional, but label its superseded clauses clearly in the live agent guide; update CLAUDE.md, docs/clients.md, and the server module overview to the released seven-tool v1.2 contract.

[onlyxItachi]

Fixed in #33 (390ad80). All five cited surfaces corrected: CLAUDE.md's release state and runtime floor, docs/clients.md's verification step, and the server/tools.py tier-1 overview now list the five digest tools plus the two capture-advisory ones.

docs/INIT_PROMPT.md stays frozen as you suggested, but CLAUDE.md no longer calls it the source of truth — it is now framed as the record of WHY the locked decisions were made, with its superseded specifics named explicitly (3.11 floor, three tools, the ncu_report-not-on-PyPI claim) so nobody validates against them by accident.

Added a regression guard so this class of drift fails CI rather than waiting to be noticed: a test extracts requires-python from pyproject and requires the live guide to state the same floor, and asserts every shipped tool name appears in the client setup guide.