fix(opencode): decouple title generation from step counter, add bounded retries (#138)

[jeonghun-jj-lee]

Summary

Every new session received the static title "New session - [timestamp]" and never updated — the chat history became a wall of identical titles.

Root Cause

Title generation in prompt.ts fires exactly once, gated on step === 1. Multiple code paths silently prevent this from ever succeeding:

1. Silent-turn guard (line 1208) does step++; continue before the title trigger is reached
2. Prose-question guard (line 1265) has the same step++; continue pattern
3. Single-message guard inside title() (line 208) bails if userMessages.length !== 1
4. No retry — title generation is attempted at most once; Effect.ignore swallows all errors

Fix

Two changes in packages/opencode/src/session/prompt.ts:

1. Replace step === 1 with a dedicated titleAttempts counter

// At initialization
let titleAttempts = 0

// At the trigger point (replacing `if (step === 1)`)
if (Session.isDefaultTitle(session.title) && titleAttempts < 3) {
  titleAttempts++
  yield* title({ ... }).pipe(Effect.ignore, Effect.forkIn(scope))
}

The counter is checked every loop pass, so retries fire immediately without waiting for a new user message. The isDefaultTitle check prevents wasted calls after success.

2. Relax the single-message guard in title()

// Before:
if (input.history.filter(real).length !== 1) return

// After:
if (input.history.filter(real).length < 1) return

Allows retries to succeed even after the second user message arrives. Double-titling prevented by the isDefaultTitle check at the caller.

Invariants preserved

• Effect.ignore stays — title generation remains non-critical and silent
• Model selection unchanged (getSmallModel → fallback)
• Title generation remains forked (never blocks the main response)
• Maximum 3 attempts is a hard cap
• The <think> tag stripping and 100-char truncation are untouched

Fixes #138