✨ Spire plugin — MVP build (phases 1-3)

Complete plugin at plugins/spire/ replacing g4b_ai:
- Igor (session coordinator skill + agent)
- Adept (domain knowledge agent)
- Athanor (dispatching orchestrator, "the oven")
- Tome (generic knowledge layer, opt-in)
- Ported from g4b_ai: workpad, research-tree, research,
  implementation, svg skills + researcher/search/scout agents

All warpspace-specific content stripped. Tome genericized.
Project-specific config via shadowed project.md reference.

plugins/spire/.claude-plugin/plugin.json

@@ -0,0 +1,9 @@
+{
+  "name": "spire",
+  "version": "0.1.0",
+  "description": "Spire — an agent orchestration system for structured development. Session coordination (Igor), domain knowledge (adepts), dispatching (athanor), knowledge management (tome), workpad, research, and implementation governance.",
+  "author": {
+    "name": "Gabor Körber",
+    "email": "gab@g4b.org"
+  }
+}