fix(tui): align session-history pagination page size

[opencode-agent]

Summary

The V2 TUI pagination implementation and its regression test disagree on the message page size.

Evidence

Commit cc29f86 defines:

const MESSAGE_PAGE_SIZE = 25

packages/tui/src/context/data.tsx uses that constant for both initial and older-page requests and for completion detection.

But packages/tui/test/cli/tui/data.test.tsx constructs a 50-message full page and asserts both requests use limit=50:

expect(pages).toEqual([{ limit: "50", order: "desc", cursor: null }])

The implementation therefore requests 25 while the checked-in test requires 50. This also means the fixture's notion of a full page does not match the implementation's completion boundary.

Expected

Define one page-size contract and use it consistently in implementation, fixtures, request assertions, and completion detection.

Source

Found during the hourly V2 slop review: https://slack.com/archives/C0BE69AHCQP/p1783490782234659

[g0rdonL]

This looks obsolete on current main (3f9dad3). Verified locally:

• MESSAGE_PAGE_SIZE no longer exists anywhere in the repo (grep -rn MESSAGE_PAGE_SIZE over all .ts/.tsx excluding node_modules returns nothing).
• packages/tui/test/cli/tui/data.test.tsx no longer contains any limit/page-size assertion — the pagination contract this issue describes was removed or rewritten since cc29f86.
• The test file passes as-is: bun test test/cli/tui/data.test.tsx from packages/tui → 7 pass, 0 fail (bun 1.3.11, macOS arm64).

No remaining implementation/test disagreement to align; probably safe to close.