rewrite planoai CLI in Rust

Add crates/plano-cli/ as a full Rust rewrite of the Python CLI.
Binary name: planoai. All subcommands ported: up, down, build,
logs, cli-agent, trace, init. Config validation and Tera template
rendering replace the Python config_generator. CI updated to use
cargo test/build instead of Python test jobs.

crates/plano-cli/templates/conversational_state.yaml

@@ -0,0 +1,36 @@
+version: v0.3.0
+
+agents:
+  - id: assistant
+    url: http://localhost:10510
+
+model_providers:
+  # OpenAI Models
+  - model: openai/gpt-5-mini-2025-08-07
+    access_key: $OPENAI_API_KEY
+    default: true
+
+  # Anthropic Models
+  - model: anthropic/claude-sonnet-4-20250514
+    access_key: $ANTHROPIC_API_KEY
+
+listeners:
+  - type: agent
+    name: conversation_service
+    port: 8001
+    router: plano_orchestrator_v1
+    agents:
+      - id: assistant
+        description: |
+          A conversational assistant that maintains context across multi-turn
+          conversations. It can answer follow-up questions, remember previous
+          context, and provide coherent responses in ongoing dialogues.
+
+# State storage configuration for v1/responses API
+# Manages conversation state for multi-turn conversations
+state_storage:
+  # Type: memory | postgres
+  type: memory
+
+tracing:
+  random_sampling: 100