fix: mount src and data volumes in container targets

Bind-mount src/ and data/ alongside plugins/ and config so the
container picks up code changes without rebuilding. Update Makefile
targets, compose file, and INSTALL.md to match.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Makefile

@@ -42,10 +42,12 @@ link: install ## Symlink to ~/.local/bin
 build: ## Build container image
 	podman build -t $(APP_NAME) .
 
-container-run: ## Run bot in container (mount config + plugins)
+container-run: ## Run bot in container (mount code + config + data)
 	podman run -d --name $(APP_NAME) \
-		-v ./config/derp.toml:/app/config/derp.toml:ro,Z \
+		-v ./src:/app/src:ro,Z \
 		-v ./plugins:/app/plugins:ro,Z \
+		-v ./config/derp.toml:/app/config/derp.toml:ro,Z \
+		-v ./data:/app/data:Z \
 		$(APP_NAME)
 
 container-stop: ## Stop and remove container
@@ -57,8 +59,8 @@ container-logs: ## Follow container logs
 update-data: ## Download/refresh local data files
 	./scripts/update-data.sh
 
-up: ## Start with podman-compose (build + detach)
-	podman-compose up -d --build
+up: ## Start with podman-compose (detach)
+	podman-compose up -d
 
 down: ## Stop with podman-compose
 	podman-compose down