fix: agent-manager model sync on config change

[IamCoder18]

Context

When a user changes the model in Settings, the sidebar chat updates correctly, but the Agent Manager continues using the old model. This happens because:

1. Agent Manager sessions store sessionOverrides that short-circuit config-based model resolution
2. NewWorktreeDialog captures session.selected() at dialog open time, including stale overrides

Closes #9349

Implementation

NewWorktreeDialog.tsx:

• Changed session.selected() to session.configModel() for model initialization
• This captures the config-based model (global + per-agent mode) without session-level overrides

session.tsx:

• Exposed configModel() function in SessionContextValue interface and context value
• Added createEffect that watches getGlobalModel() and clears sessionOverrides when the config model changes
• The effect only clears overrides that matched the OLD config model (likely default values), preserving intentional user overrides

The reactive effect uses SolidJS signals to track the previous config model and compares it with the current value. When they differ, overrides matching the old config are removed via produce() for batched store updates.

Screenshots

Before

before.mp4

After

after.mp4

How to Test

1. Open the Agent Manager and create a worktree (observe the model in the dialog)
2. Change the model in Settings (Sidebar → Settings → Model)
3. Open the New Worktree dialog again - it should now show the newly selected model
4. Create a new worktree - it should use the new model, not the old one
5. Existing worktree sessions should also reflect the new model (overrides cleared if they matched old config)

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Previous Issues (all resolved)

All issues raised across this review cycle have been addressed:

File	Line	Issue	Status
packages/kilo-vscode/webview-ui/src/context/session.tsx	782	lastConfigModel() read inside effect causing spurious double-run	✅ Fixed — untrack(() => lastConfigModel()) used
packages/kilo-vscode/webview-ui/src/context/session.tsx	808	Guard skipped cleanup when config model transitioned to null	✅ Fixed — else branch handles null transition
packages/kilo-vscode/webview-ui/agent-manager/NewWorktreeDialog.tsx	124, 444	overridden memo and reset button still used session.selected() instead of session.configModel()	✅ Fixed — both changed to session.configModel() in commit a8f3a69

Files Reviewed (3 files)

• packages/kilo-vscode/webview-ui/src/context/session.tsx — 0 issues
• packages/kilo-vscode/webview-ui/agent-manager/NewWorktreeDialog.tsx — 0 issues
• .changeset/agent-manager-model-sync.md — 0 issues

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_{Reviewed by claude-4.6-sonnet-20260217 · 331,056 tokens}

_{Review guidance: REVIEW.md from base branch main}

[marius-kilocode]

@IamCoder18 my bot sais this fix doesn't work for the new worktree modal? (cmd shift n), is this true?

NewWorktreeDialog.tsx:88 initializes from session.configModel().
But NewWorktreeDialog.tsx:122-127 still compares against session.selected().
And NewWorktreeDialog.tsx:444 resets back to session.selected().

[IamCoder18]

@IamCoder18 my bot sais this fix doesn't work for the new worktree modal? (cmd shift n), is this true?

NewWorktreeDialog.tsx:88 initializes from session.configModel(). But NewWorktreeDialog.tsx:122-127 still compares against session.selected(). And NewWorktreeDialog.tsx:444 resets back to session.selected().

You're right. I had only tested local sessions, not sessions in worktrees or the New Worktree modal. I'll fix this later today.

[IamCoder18]

@IamCoder18 my bot sais this fix doesn't work for the new worktree modal? (cmd shift n), is this true?

NewWorktreeDialog.tsx:88 initializes from session.configModel(). But NewWorktreeDialog.tsx:122-127 still compares against session.selected(). And NewWorktreeDialog.tsx:444 resets back to session.selected().

@marius-kilocode Fixed!

2026-05-22.17-18-16.mp4

[marius-kilocode]

Looks good @IamCoder18, thanks for the fix!