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>

README.md

@@ -62,6 +62,7 @@ Ask naturally or use slash commands as shortcuts.
 | `/draft <topic>` | Paper-style draft from research findings |
 | `/autoresearch <idea>` | Autonomous experiment loop |
 | `/watch <topic>` | Recurring research watch |
+| `/outputs` | Browse all research artifacts |
 
 ---
 
@@ -76,19 +77,21 @@ Four bundled research agents, dispatched automatically.
 
 ---
 
-### Tools
+### Skills & Tools
 
-- **[AlphaXiv](https://www.alphaxiv.org/)** — paper search, Q&A, code reading, persistent annotations
+- **[AlphaXiv](https://www.alphaxiv.org/)** — paper search, Q&A, code reading, annotations (via `alpha` CLI)
 - **Docker** — isolated container execution for safe experiments on your machine
 - **Web search** — Gemini or Perplexity, zero-config default
 - **Session search** — indexed recall across prior research sessions
 - **Preview** — browser and PDF export of generated artifacts
+- **Modal** — serverless GPU compute for burst training and inference
+- **RunPod** — persistent GPU pods with SSH access for long-running experiments
 
 ---
 
 ### How it works
 
-Built on [Pi](https://github.com/badlogic/pi-mono) for the agent runtime, [alphaXiv](https://www.alphaxiv.org/) for paper search and analysis, and [Docker](https://www.docker.com/) for isolated local execution. Every output is source-grounded — claims link to papers, docs, or repos with direct URLs.
+Built on [Pi](https://github.com/badlogic/pi-mono) for the agent runtime, [alphaXiv](https://www.alphaxiv.org/) for paper search and analysis, and CLI tools for compute and execution. Capabilities are delivered as [Pi skills](https://github.com/badlogic/pi-skills) — Markdown instruction files synced to `~/.feynman/agent/skills/` on startup. Every output is source-grounded — claims link to papers, docs, or repos with direct URLs.
 
 ---