Add Codex session support and prepare 0.3.0

[lifrary]

Summary

• Introduce a session-source contract and separate Claude discovery from shared session resolution.
• Support Codex discovery/imports, normalized messages and tools, duplicate notifications, compaction records, CLI/MCP source selection, and source-tagged JSON.
• Isolate stars by source, redact tool labels before truncation, and update installed-artifact smoke coverage and runtime guidance.
• Prepare version 0.3.0 with synchronized metadata and committed bundles, in three focused commits.

Verification

• seca-vs: lint, TypeScript 7 and TypeScript 6 checks, all 626 tests, build, release consistency, installed-tarball CLI/MCP smoke, and dependency audit (0 vulnerabilities).
• Corrected synthetic metadata fixture rechecked with 37 CLI/MCP tests and installed-tarball smoke.
• macOS: bundled CLI/MCP release checks and strict Codex import.
• Three real local Codex rollouts passed strict heuristic analysis without warnings; private logs were not copied or committed.

Compatibility and limits

• Discovery defaults to Claude; use --source codex. Explicit files auto-detect their format.
• Stars now live in source-specific directories; old flat-directory history is not read or migrated.
• Resume/fork output is a context prompt, not a native agent command or file restore.
• Directory replacement guards are not a sandbox against a process with write access to the session directories.

Publication

npm authentication currently returns HTTP 401. This PR prepares the release; it does not claim npm publication, and release notes remain marked unreleased.