chore: add changesets for post-v0.12.0 commits

Cover FN-3024 experimental agent onboarding modal, FN-2981 droid-cli
auth/status routes, and the CLI session bloat + quick chat continuity
fix that landed without changesets.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.changeset/fix-cli-session-bloat-and-quick-chat-continuity.md

@@ -0,0 +1,8 @@
+---
+"@runfusion/fusion": patch
+---
+
+Fix two related CLI-session issues that caused resumed sessions to balloon in size and quick chat to lose continuity:
+
+- Resumed pi-claude-cli and droid-cli sessions were re-sending the entire conversation transcript over stdin every iteration. `buildResumePrompt` anchored on the last user message and walked forward through preceding tool results, but the only user message stayed at index 0, so each turn duplicated the original query plus a growing stack of tool results into the on-disk session. Anchor on the last assistant message and slice forward instead, so only the genuine delta since the previous turn is sent.
+- Quick chat created a fresh CLI session per user message and faked continuity by stuffing the last 50 messages into the prompt as a "## Previous Conversation" block. Replace that with real session continuity: `chat_sessions` gains a `cliSessionFile` column (migration 56) and ChatManager now reuses the existing pi SessionManager file when present, creating a fresh one on the first turn and persisting its path. The prompt now carries only the new user content.

.changeset/fn-2981-droid-cli-auth.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": minor
+---
+
+Add Droid CLI provider integration: new auth and status routes (`GET /api/providers/droid-cli/status`, `POST /api/auth/droid-cli`) plus a Settings toggle hook for enabling Droid CLI–based authentication. Wired into the onboarding provider card so users can connect Droid CLI from the same flow as the other providers.

.changeset/fn-3024-experimental-agent-onboarding.md

@@ -0,0 +1,5 @@
+---
+"@runfusion/fusion": minor
+---
+
+Add an experimental agent onboarding modal that streamlines the handoff from first-run onboarding into the create-agent form, so new users land on a configured agent draft instead of an empty Settings page. Backed by lifecycle tests and gated behind the experimental flag documented in the onboarding docs.