feat(tui): add configurable message_limit for session history

[CasualDeveloper]

Summary

• Add tui.message_limit config option to control how many messages are loaded per session (default: 100)
• Add tui.session_list_limit config option to control how many sessions are shown in the session picker (default: 150)

Closes #6137
May also resolve #4918

Usage

{
  "tui": {
    "message_limit": 500,
    "session_list_limit": 200
  }
}

Changes

File	Change
packages/opencode/src/config/config.ts	Add message_limit and session_list_limit to TUI schema
packages/opencode/src/cli/cmd/tui/context/sync.tsx	Use message_limit config
packages/opencode/src/cli/cmd/tui/component/dialog-session-list.tsx	Use session_list_limit config
packages/sdk/*	Generated types

[Copilot]

Pull request overview

This PR adds a configurable message_limit option to control the number of messages loaded per session in the TUI. The default value remains 100, but users can now configure it up to 10,000 messages through the config file.

• Add message_limit configuration field to TUI schema with validation constraints (1-10,000)
• Update implementation to use the configured value with fallback to 100
• Generate corresponding TypeScript type definitions

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/sdk/openapi.json	Adds message_limit field to the schema with integer constraints (1-10,000) and description
packages/sdk/js/src/v2/gen/types.gen.ts	Generated TypeScript types for the new message_limit config option
packages/sdk/js/src/gen/types.gen.ts	Generated TypeScript types with incorrect default value in documentation
packages/opencode/src/config/config.ts	Adds Zod schema validation for message_limit with proper constraints
packages/opencode/src/cli/cmd/tui/context/sync.tsx	Updates message loading to use configured limit with fallback to 100

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[CasualDeveloper]

Fixed the inconsistent default value in the SDK types (was 500, now correctly 100). Thanks Copilot!

[CasualDeveloper]

Fixed second hardcoded 100 in the message.updated event handler at line 191. Without this, new messages arriving during active sessions would trim the array back to 100, defeating the configurable limit.

[CasualDeveloper]

I have a working implementation ready - typechecks pass.

[ariane-emory]

@CasualDeveloper I also want to see this feature. I've had a half-finished PR in my pocket for a while that addresses this (and also makes the length of session_list similarly configurable) I haven't found the time to finish it and yours looks like it may be cleaner than mine.

I cordially invite you to steal anything you think might be useful from my unfinished PR: ariane-emory#43

The team may (or may not) conclude that this also resolves my original Issue on the topic, #4918.

[CasualDeveloper]

@ariane-emory Thanks for linking your PR! I've incorporated session_list_limit from your work. Kept the implementation simpler (no "none" option, proper types instead of as any casts). Added a reference to #4918 in the PR description.

[CasualDeveloper]

Re-committed with valid GPG signature. PR ready.