docs: rework README around agent setup and refresh the docs

[dash0-dev]

Summary

The README was a 600-line mix of pitch, reference, and troubleshooting, and it undersold the newest differentiator: SyncTray can be set up end-to-end by an AI agent through the synctray CLI and the file-backed config. This PR turns the README into a product page (189 lines) and moves the depth into docs/, fixing stale facts along the way.

Changes

• README: new tagline and "Why SyncTray"; a "Let your agent set it up" section with a two-line prompt that covers rclone and SyncTray, linking to the full guide; Stream/offline/Cache Only, fallback, and filters pitched as features; one-line Homebrew install above the fold; docs table and FAQ.
• New docs: docs/user-guide.md, docs/agent-setup.md (incl. ground rules to paste into AGENTS.md/CLAUDE.md), docs/cli.md (all 19 commands, output, exit codes), docs/configuration.md (every profile field and default), docs/troubleshooting.md, and a docs/README.md index.
• Drift fixed: the CLI table listed 11 of 19 commands; "rclone must be configured first" (the wizard creates remotes for 7 providers); a "Resync" button that is now Fix Sync Issues; Paused state missing; build-from-source needs CODE_SIGNING_ALLOWED=NO; local-change sync debounce is 5 s, not 15 s (also in CLAUDE.md).
• DEVELOPMENT.md: Team-prefixed App Group id, .dev bundle ids, a Testing section (--self-test, schema check), commit convention + /beta releases moved here, and the telemetry section rewritten (30 s delta export, 50+ instruments, privacy list matching the in-app sheet; it previously claimed profile names aren't sent).

Follow-ups (not in this PR)

• docs/assets/profile-stream.png still shows the old "Requires macFUSE" warning and the old cache path, so the README no longer uses it. New captures would help: the Finder "Available Offline" menu, Cache Only, and a short GIF of an agent running the setup.
• The GitHub repo description still says "rclone sync monitoring … no dependencies". Suggested: "Google Drive-style sync, streaming, and offline files for any rclone storage. Native macOS menu bar app, agent-ready CLI."
• CLAUDE.md is ~124 KB, far above the hot-path budget; worth splitting into .claude/rules/ files.

[dash0-dev]

✅ No issues found

Re-review of the 3-line fix in docs/cli.md. The rewritten claim holds against the source: the CLI exits before the app's watchers and timers start, and enable, install and mount hand work to launchd. Prior finding resolved.

Checked: 1 of 1 changed file read · no possible issues found

Progress: open review threads 1 → 0 across the last 2 reviews

Review details

Gate	Status	Details
Description vs. code	✅	Matches the diff: README rework, six new docs pages, DEVELOPMENT.md and CLAUDE.md fixes; new commit rewords docs/cli.md.
Prior review feedback	✅	Earlier review comments are resolved.
Documentation	✅	Purpose, every changed surface, and out-of-scope follow-ups are all described.
Self-review signals	✅	No debug logs, leftover TODOs, or unreviewed stubs.
Code review	✅	The multi-lens review found no blocking issues.

Found

Quality — produced 0 → posted inline 0 · cleared 0 · carried forward 0 · deferred 0 · below-bar 0

Run

incremental-quick · 3 lines in delta · tier quick · depth checkout
Integrations — none
CI — still pending: test · 1 passed
Memories — no relevance rules or lessons consulted

^{Nothing to report — standards (skipped), optimality (skipped), measurability (skipped), severity, reach diagram (impact graph found no consumer or importer), 0 files skipped.}

^{pr-reviewer · commit 303d190 · incremental review, delta since 9cf9c41 · how these findings are produced · updated Oct 9, 2026 7:09am UTC}

[dash0-dev]

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