fix(desktop): offer redeploy when editing a deployed remote agent

[aksOps]

Problem

Editing a provider-backed (remote) agent behaves as if the agent were local: Save writes the local record and nothing reaches the host. The remote unit keeps running with the env file from its last deploy, and every apply mechanism is local-gated:

• the auto-restart policy never fires for a non-local backend (autoRestartPolicy.ts)
• the saved-while-stopped toast bails because "deployed" counts as active
• needs_restart is derived from the local process table, so the restart badge never appears
• the profile panel Restart button was gated to backend.type === "local"

The only way to apply an edit was a manual !shutdown message followed by Deploy — undiscoverable.

Fix

The start command already IS the redeploy for provider records: it rebuilds the deploy payload from current state, and the SSH provider rewrites the unit env file and unconditionally restarts the unit (verified idempotent, deploy.rs). This PR wires the edit experience to that path:

• Post-save redeploy offer — saving an edit that touches deploy-visible config on a deployed provider record shows a toast with a Redeploy now action. Offered, not automatic: deploy restarts the remote unit unconditionally, and the local auto-restart policy's mid-turn safety gates (working signal, 3-min quiescence) have no remote equivalent yet.
• Persistent Redeploy button — the profile panel restart action is un-gated for provider records and labeled Redeploy; respawnManagedAgentWithRules already skips the local stop for provider backends.
• Linked-definition model writes count — a model edit on a linked instance travels via the definition (the record patch omits model), so useInstanceModelDefinitionWrite now exposes willWrite and the offer counts it as host-visible.
• Name-only edits do not prompt (the rename syncs to the relay via kind:0 immediately; the host copy is cosmetic).

Decision logic lives in redeployAfterEdit.ts (pure, unit-tested); toast selection is consolidated in showAgentPostSaveToasts so the dialog stays a thin caller and under its file-size ratchet.

Verification

• pnpm run typecheck — clean
• pnpm exec biome check on changed files — clean
• pnpm run check:file-sizes — clean (dialog at exactly its ratchet ceiling)
• pnpm test — 4193 pass / 0 fail (includes new redeployAfterEdit.test.mjs)

Not verified: live end-to-end against a real SSH host from a Windows build — needs the desktop app rebuilt and a deployed remote agent.

Follow-ups (out of scope)

• Remote model probing in the edit dialog (the field is deliberately free-text today; the create flow's probe_provider_models machinery is reusable from a record's backend field alone)
• A remote needs_restart drift signal + auto-apply with proper mid-turn gates
• Redeploy affordance in the agents list rows / members sidebar