Replace Pi tool registrations with skills and CLI integration

- Remove all manually registered Pi tools (alpha_search, alpha_get_paper,
  alpha_ask_paper, alpha_annotate_paper, alpha_list_annotations,
  alpha_read_code, session_search, preview_file) and their wrappers
  (alpha.ts, preview.ts, session-search.ts, alpha-tools.test.ts)
- Add Pi skill files for alpha-research, session-search, preview,
  modal-compute, and runpod-compute in skills/
- Sync skills to ~/.feynman/agent/skills/ on startup via syncBundledAssets
- Add node_modules/.bin to Pi subprocess PATH so alpha CLI is accessible
- Add /outputs extension command to browse research artifacts via dialog
- Add Modal and RunPod as execution environments in /replicate and
  /autoresearch prompts
- Remove redundant /alpha-login /alpha-logout /alpha-status REPL commands
  (feynman alpha CLI still works)
- Update README, researcher agent, metadata, and website docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

skills/session-search/SKILL.md

@@ -0,0 +1,26 @@
+---
+name: session-search
+description: Search past Feynman session transcripts to recover prior work, conversations, and research context. Use when the user references something from a previous session, asks "what did we do before", or when you suspect relevant past context exists.
+---
+
+# Session Search
+
+Use the `/search` command to search prior Feynman sessions interactively, or search session JSONL files directly via bash.
+
+## Interactive search
+
+```
+/search <query>
+```
+
+Opens the session search UI. Supports `resume <sessionPath>` to continue a found session.
+
+## Direct file search
+
+Session transcripts are stored as JSONL files in `~/.feynman/sessions/`. Each line is a JSON record with `type` (session, message, model_change) and `message.content` fields.
+
+```bash
+grep -ril "scaling laws" ~/.feynman/sessions/
+```
+
+For structured search across sessions, use the interactive `/search` command.