v2.0.1 — Independent re-audit pass

Independent re-audit pass — two fresh review passes (general Go code quality, and a
security/threat-model review re-deriving its own judgment rather than trusting v2.0.0's
prior hardening claims) against the already-shipped v2.0.0 code, with all confirmed
findings fixed. go build/vet/test/govulncheck/gosec/staticcheck all still
report clean; nothing here was a tool-detectable issue — that's exactly why a second,
independent read mattered.

Fixed:

• Data race on the tray's status string (tray.go) — written by the background sync
  goroutine, read from a menu-click callback on a different goroutine, with no
  synchronization. Now a small mutex-guarded statusHolder.
• Redaction blind spot: chromedp's own internal logging defaulted to Go's stdlib
  log.Printf (targets stderr), entirely bypassing this program's stdout redactor while
  a live session held the injected sessionKey cookie. Wired chromedp.WithErrorf/
  WithLogf to route through the same redact() every other output path uses.
• VBScript injection: install-task's optional outDir argument was spliced
  unescaped into the generated logon-autostart .vbs file; an embedded " could break
  out of the intended quoted argument. Now escaped per VBScript's own quote-doubling
  convention, with a test case that exercises exactly that input.
• Silent multi-org gap: the harvester always picked the account's first organization
  with no signal if a second (e.g. a Team workspace) existed. Now logs a warning so "did
  I get everything?" has an answer.
• Non-atomic state writes: .sync-state.json was written directly; now written to a
  temp file and renamed into place, so a crash or overlapping run can't leave a
  truncated/corrupt state file.
• Byte-unsafe truncation: trunc() sliced strings by byte index, which can split a
  multi-byte UTF-8 rune in half — reachable in practice via German titles (umlauts, ß)
  or emoji, producing a corrupted character in a filename. Now rune-safe.
• Documentation honesty pass on SECURITY.md: several claims read stronger than what the
  code actually enforces (the exact scope of TestNetworkEgressIsClaudeOnly's literal-
  only URL matching, the redaction guarantee's stdout-vs-stderr boundary before the
  chromedp fix above, "one secret" undercounting the broader on-disk temp-copy
  footprint). Clarified each; added an explicit section on what the regex-based
  invariant tests do and don't protect against.
• Minor: an inaccurate code comment (attributed a Chrome cookie-encryption detail to
  "v10" when it's actually v20 App-Bound Encryption), an imprecise doc comment ("Task-
  Scheduler" when the actual mechanism is a Startup-folder .vbs drop), and an
  unbounded-growth nit in the redactor's secrets list across long daemon uptimes
  (deduped on register).