Decommissioned probe installs retain journal, database and logs indefinitely

[willwashburn]

Problem

A decommissioned probe install keeps everything forever. Observed under ~/.agentworkforce/probe/:

• bc637…: all 9 delivery jobs cancelled, no config.json, yet history.db is 3.8 GB + 202 MB WAL, delivery_journal holds 14.5k rows / 99 MB (retained_bytes 37% of cap), and collector.log is 307 MB.
• The live install's collector.log is 55 MB after two days.

Nothing reclaims journal rows once no subscription exists, nothing rotates collector.log, and nothing removes an install's directory when it is decommissioned.

Fix

• When no non-cancelled job / subscription remains, compaction drops the whole journal and shadow tables (nothing can consume them).
• collector.log rotates (10 MB, keep 3).
• Decommissioning an install (cloud uninstall, account switch, installs listing an entry with no config.json) removes its directory after the collector is stopped; installs --json never lists a directory without a valid config.

Related: #53 (evidence-table retention for the history database itself — separate concern).

Acceptance

• Test: cancelling the last job leaves delivery_journal and delivery_shadow empty after the next compaction and retained_bytes at 0.
• Test: log rotation keeps the file under the cap.
• Test: an install directory without config.json is removed by the decommission path and absent from installs --json.

[willwashburn]

Root cause context and the full analysis: #244. Fixes for #240, #241, #242 and #243 are independent PRs; desktop follow-up: https://github.com/AgentWorkforce/relay-desktop/issues/23.

[willwashburn]

Correction to the fix section: history.db is retained on disconnect and by the decommissioned-install sweep. delivery_state.origin_id is random per database and the cloud keys rows, machine identity and per-session aggregates by origin; a fresh DB on reconnect would upload every pre-existing session beside its old rows (doubled events/cost, phantom second machine) and, with a deterministic origin, restart revisions at 1 so updates to old sessions would be dropped. The sweep removes logs, stages, locks and status JSON and compacts the journal/receipts; evidence-table bulk is #53.

[barryollama]

The probe (cloud client, delivery journal, install management) moved to relay-desktop/probe/, so this is now tracked at AgentWorkforce/relay-desktop#77. Leaving this open for a maintainer to close.