fix: Remove agents-llama service references from docs and formulas (#846)

- AGENTS.md: Replace agents-llama and agents-llama-all rows with generic
  'Local-model agents' entry pointing to docs/agents-llama.md
- formulas/release.sh: Remove agents-llama from docker compose stop/up
  commands (line 181-182)
- formulas/release.toml: Remove agents-llama references from restart-agents
  step description (lines 192, 195, 206)

These changes complete the removal of the legacy ENABLE_LLAMA_AGENT activation
path. The release formula now only references the 'agents' service, which is
the only service that exists after disinto init regenerates docker-compose.yml
based on [agents.X] TOML sections.

formulas/release.toml

@@ -189,10 +189,10 @@ Restart agent containers to use the new image.
    - docker compose pull agents
 
 2. Stop and remove existing agent containers:
-   - docker compose down agents agents-llama 2>/dev/null || true
+   - docker compose down agents
 
 3. Start agents with new image:
-   - docker compose up -d agents agents-llama
+   - docker compose up -d agents
 
 4. Wait for containers to be healthy:
    - for i in {1..30}; do
@@ -203,7 +203,7 @@ Restart agent containers to use the new image.
    - done
 
 5. Verify containers are running:
-   - docker compose ps agents agents-llama
+   - docker compose ps agents
 
 6. Log restart:
    - echo "Restarted agents containers"