feat(ui): add agent deletion controls

[jayesh9747]

Summary

Closes#429

Changes

• Add a delete action and confirmation dialog to each Agents Library row when the server exposes deleteAgent.
• Preserve existing chats while clearing stale active-agent and history-filter state after deletion.
• Wire the bundled TrueForge adapter to the existing agents list and DELETE /api/v1/agents/{agent_id} SDK routes.
• Keep custom servers capability-safe by omitting deleteAgent when no callback is provided.
• Add the required UI package changeset and update the server-contract documentation.

How was this tested?

• pnpm test:trueforge-ui — 130 test files / 847 tests passed, including package build and export smoke tests.
• pnpm --filter @truefoundry/trueforge-ui typecheck
• pnpm --filter @truefoundry/trueforge-ui lint
• pnpm format:check

Checklist

• Tests added for success, cancellation, failure, unsupported hosts, adapter routing, and idempotency.
• No hand-edits to generated OpenAPI or SDK code.
• Documentation and changeset updated.

---

Note

Medium Risk
Deletes are destructive and touch shell navigation state after removal; behavior is gated on optional server support and covered by tests, but wrong adapter logic could remove the wrong backend resource.

Overview
Adds agent deletion to the Agents Library when the host server exposes deleteAgent: a trash action per row, a confirmation dialog, success/error feedback, and a list refresh via invalidateAgentsList. After a successful delete, the UI clears a matching history filter and navigates away if the deleted agent was active (draft or library home depending on composer mode).

createTrueFoundryServer no longer installs a stub that throws when deleteAgent is omitted—it only attaches the method when a callback is provided, matching custom-server behavior where missing optional ports hide controls instead of failing at runtime.

The bundled TrueForge builder adapter implements deleteAgent by resolving the agent id from the list API and calling DELETE /api/v1/agents/{id} (no-op if the name is already gone). Docs and the BYO checklist now state that deleteAgent is invoked from the library when present.

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[changeset-bot]

🦋 Changeset detected

Latest commit: 44c4a65

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@truefoundry/trueforge-ui	Minor
frontend	Patch

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[kumarsks619]

@jayesh9747 please add relevant screenshots/screen-recording