feat(agents): add history, activity and learned suggestions

[astyfx]

Summary

Stacked on #605. Agents keep a version history, show their activity on the agent page, and learn instruction changes from corrections.

Changes

Features

• agents: History tab lists the last 10 saves with the fields that differ from now, a Ran mark and Restore (restores are themselves recorded)
• agents: activity counts (assignments, running, needs you, couldn't start, last used) and the Work list sit on the agent page; tabs are Settings and History
• agents: learned suggestions: after a corrected turn in a task a custom agent runs, one utility-model request may propose revised instructions to Apply, Edit or Dismiss; on by default, per-agent switch to turn it off, at most one request per task and three open suggestions per agent

Test Evidence

• bun run test:ci passes
• bun run build:pages passes
• new tests: agent-learned-suggestions, agent-revisions; agents-tab covers the suggestions card

Notes

• The learning request sends only user and agent message text from the task and runs read only without bound secrets.
• New settings keys: customAgentRevisions, agentSuggestions, agentLearningDisabled.
• Schedule and event triggers for agents are left for a follow-up.

[upwind-code-us]

Upwind Code Scan - ✅ Passed

0 newly introduced vulnerabilities · 0 resolved · 42 total in this PR vs main

Total breakdown: 🔶 5 High | 🟡 34 Medium | 🟢 3 Low

View full analysis in Upwind Console

Scan completed in 17s

Scan history (2 scans)

Commit	Scanned at	New	Resolved	Net
144b2b3	2026-09-29 15:26 UTC	0	0	0
4b1e331 <	2026-09-30 07:14 UTC	0	0	0

Last scanned: 4b1e331 · 2026-09-30 07:14 UTC

[upwind-code-us]

Upwind IaC Scan - ✅ Passed

0 newly introduced misconfigurations · 0 resolved · 0 total in this PR vs main

View full analysis in Upwind Console →

Scan completed in 2s

Scan history (2 scans)

Commit	Scanned at	New	Resolved	Net
144b2b3	2026-09-29 15:26 UTC	0	0	0
4b1e331 <	2026-09-30 07:14 UTC	0	0	0

Last scanned: 4b1e331 · 2026-09-30 07:14 UTC

[heath-s]

Approved