refactor(claude-md): split shared base into module fragments, inject name at runtime

Move every agent-specific instruction out of the shared container/CLAUDE.md
so the base is genuinely universal. Persona/identity now comes from the
system-prompt addendum (buildSystemPromptAddendum now takes assistantName
and prepends "# You are {name}"). Per-module instructions live alongside
each MCP tool source:

  container/agent-runner/src/mcp-tools/core.instructions.md
  container/agent-runner/src/mcp-tools/scheduling.instructions.md
  container/agent-runner/src/mcp-tools/self-mod.instructions.md

composeGroupClaudeMd() scans that directory and emits `module-<name>.md`
fragments as symlinks to /app/src/mcp-tools/<name>.instructions.md (valid
via the existing RO source mount). Skill fragments renamed to
`skill-<name>.md` for naming consistency with `module-*` and `mcp-*`.

Mount tightening so composer-managed files can't be clobbered by agent
writes: nested RO mounts for /workspace/agent/CLAUDE.md and
/workspace/agent/.claude-fragments/. CLAUDE.local.md (per-group memory)
stays RW as the only writable CLAUDE.md-family file.

.gitignore: ignore CLAUDE.local.md, .claude-shared.md, .claude-fragments/
everywhere, and simplify groups/ rules to ignore the whole tree (per-
installation state, not tracked).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/config.ts

@@ -5,13 +5,7 @@ import { readEnvFile } from './env.js';
 import { isValidTimezone } from './timezone.js';
 
 // Read config values from .env (falls back to process.env).
-const envConfig = readEnvFile([
-  'ASSISTANT_NAME',
-  'ASSISTANT_HAS_OWN_NUMBER',
-  'ONECLI_URL',
-  'ONECLI_API_KEY',
-  'TZ',
-]);
+const envConfig = readEnvFile(['ASSISTANT_NAME', 'ASSISTANT_HAS_OWN_NUMBER', 'ONECLI_URL', 'ONECLI_API_KEY', 'TZ']);
 
 export const ASSISTANT_NAME = process.env.ASSISTANT_NAME || envConfig.ASSISTANT_NAME || 'Andy';
 export const ASSISTANT_HAS_OWN_NUMBER =