fix: make app boot recover instead of hanging on the loader - #337

🟢 Confidence 9/10 · safe to merge
Session- and org-gate changes touch auth-adjacent state, but each risky path has a story test I traced through the update and view code.
_{quality 100/100 · no findings · tests covered · risk medium}

The boot path now surfaces failures instead of hanging: live queries report a stall, the org gate has explicit Found/NotFound/Stalled states, stalled loaders offer a reload, and an unreachable API no longer signs the user out. Contained, and pinned by tests that exercise each of those paths.

• readSession fails when the API cannot answer instead of silently returning SignedOut
• liveQueryStream takes onStalled, and appLoader shows a note plus a Reload button
• orgLoad (Found/NotFound/Stalled) replaces loadedOrgSlug, and an unknown workspace shows a not-found page
• electricOnError retries a 401 with a fresh token and stops the shape on other errors

_{8785304 · Updated on every push. Reply "won't fix" to dismiss a finding, or mention @maple-review-bot to ask about one.}