chore(release): 0.4.5-next.0

[justin-carper]

Pre-release cut for @next testing. Bundles the five merged PRs on top of stable 0.4.4:

• fix(provider): note file/dir @-mentions as text instead of failing the turn #58 note file/dir @-mentions as text instead of failing the turn
• fix(session): retry resumed turns that fail against an expired Cursor agent #52 retry resumed turns that fail against an expired Cursor agent
• feat: warn when installed plugin lags registry latest #33 warn when installed plugin lags registry latest
• feat(session): warm resume for multi-message prompt interjections #57 warm resume for multi-message prompt interjections
• fix(provider): deliver opencode system prompt to Cursor via the rules channel #56 deliver opencode system prompt to Cursor via the rules channel

Bumps package.json/lockfile to 0.4.5-next.0 and updates CHANGELOG. Once merged, tag v0.4.5-next.0 on the merge commit → Release workflow publishes to the @next dist-tag and marks a GitHub pre-release (stable latest stays at 0.4.4).