feat: Agent Orchestrator — multi-project agent dashboard

Tauri + Svelte 5 + Rust application for orchestrating multiple AI coding agents.
Includes Claude, Aider, Codex, and Ollama provider support, multi-agent
communication (btmsg/bttask), session anchors, plugin sandbox, FTS5 search,
Landlock sandboxing, and 507 vitest + 110 cargo tests.

.claude/rules/02-error-handling.md

@@ -0,0 +1,13 @@
+# Error Handling (PARAMOUNT)
+
+Every error must be handled explicitly. Silent failures are the most dangerous bugs.
+
+## Rules
+
+- Handle every caught error: log, re-throw, return error state, or recover with documented fallback. Empty catch blocks are forbidden.
+- Catch specific exceptions, not blanket `catch (e)`. Propagate errors to the level that can meaningfully handle them.
+- Async: handle both success and failure paths. No unhandled rejections or fire-and-forget.
+- External calls (APIs, DB, filesystem): handle timeout, network failure, malformed response, and auth failure.
+- Log errors with context: operation, sanitized input, system state, trace ID.
+- Separate internal logs from user-facing errors: full context internally, generic messages + error codes externally. Never expose stack traces or internal paths in responses (CWE-209).
+- Never log credentials, tokens, PII, or session IDs (CWE-532).