docs: add a review agenda and config compatibility rules

Reviewing the project used to mean re-stating what to look at every time.
docs/REVIEW.md now holds that agenda once — nine areas, each anchored to this
codebase — and both entry points point at it rather than copying it: the
/review-project command in .claude/commands, and a section in CLAUDE.md so a
plain-language review request lands in the same place.

STANDARDS.md gains a "Config file compatibility" section. The project has
applied the same rule three times (Theme, JobListView, TimeoutSeconds) without
ever writing it down: a new Config field is omitempty and its zero value means
the previous behavior, a meaningful zero is never backfilled on load, and an
unrecognised enum value reads as the default through one shared helper. With no
migration step and hand-editable files, that is what keeps older configs working.

Also removes docs/PLAN-compact-job-list.md, implemented in edabc57 — everything
but the version bump, which now waits for the release along with the rest of
the Unreleased section. .claude/settings.local.json is ignored so the shared
command can be tracked without per-developer permissions.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -49,6 +49,7 @@ GoSentry is built and tested on **Windows** and **Linux**:
 - [Roadmap](docs/ROADMAP.md) — planned work larger than a single bug fix
 - [Architecture](docs/ARCHITECTURE.md) — component interaction model
 - [Standards](docs/STANDARDS.md) — quality rules and intentional behavior
+- [Review](docs/REVIEW.md) — what a whole-project review looks at
 - [Development](docs/DEVELOPMENT.md) — build instructions, project layout, dependencies
 - [Tests](docs/TESTS.md) — test suite layout and how to run it
 - [Performance](docs/PERFORMANCE.md) — measured performance findings