v0.5.0

Ports pi's SettingsManager stack into the coding-agent core, with DataStore-backed settings storage in the app. AgentSession now runs on a single repository-backed SettingsManager, including scoped models and thinking-level switching, and the app's own ModelSettings persistence and SessionSeeding are gone in favor of pi's createAgentSession factory.

Session behavior moves closer to pi: preflight and compaction checkpoints, manual compaction, the abort contract and next-turn refresh, summarization guards and cut-point math, and pi's session test suite ported to Kotlin. The session tree is consolidated into SessionManager behind a read-only view, tree rows project from the ported getTree, and web_search is reworked as Pathfinder-owned tool code.

Performance: streaming delivery is decoupled from the Main thread, transcript recomposition and parsing hot paths are eliminated, session listing and appends are cheaper, session summary refreshes are coalesced to once per agent run, and snapshot content is cached per block to avoid quadratic per-delta cost.