New projects from conversation (M2.5, PR B)

- propose_project(name, purpose, decisions) in a conversation goes up for
  a go-ahead (checked: a slug, not an existing project, no trailing
  question).
- On go, the provisioning checklist (D1): a repository with a README,
  protection on its default branch, the agent as a collaborator, a build
  VM, a deploy key, and the project entry as YAML with <...> to fill in.
- On "done", the agent reads its configuration again and adds the new
  project live (build_loop_agent(load=...); only additions), then checks
  what was provided (D4, verified, not assumed): permissions and
  protection as it sees them, then on a throwaway branch with an empty
  commit, a branch push must succeed and a push to the default branch and
  merging its own PR must be refused. The check's PR is closed and its
  branch deleted. Failures are said per item; nothing starts.
- Checked: the tracking issue (the distilled decisions, carrying the new
  item's ID), and the project's item, agreed and labelled `design`, whose
  first milestone is ARCHITECTURE.md and the build plan. A conversation
  waiting on provisioning doesn't close as idle.
- The walk replays exactly from its seed (item IDs too), and event IDs
  stay unique across simulated restarts, as a server's are.
- The test config holds output to 8192 tokens, under the test key's
  per-request cost cap.

Tests: new-project unit tests (checklist and its YAML parse as config, done
before the entry, what isn't set up, a checked project's record and first
PR, an existing name), protection enforced by a hook on the fake forge,
the walk proposing projects and saying done, and an e2e new project in a
repository the test operator provisions from the agent's checklist.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

tests/integration/nisse-test.yaml

@@ -27,6 +27,10 @@ projects:
 llm:
   base_url: https://litellm.dongar.net
   token: ${NISSE_LLM_TOKEN}
+  # The test key caps each request's worst-case cost ($0.10): input plus
+  # this much reserved output. The test agent's replies are short, so half
+  # the default leaves room for ~40k input tokens on Haiku.
+  max_output_tokens: 8192
 
 # The live tests exercise the gated loop and the routes over a real proxy,
 # not local-model competence (measured separately by test_model_capability),