Milestones and review in the new loop (M2.1, PR C)

A work item starts from a fresh workspace: fetch, set aside (never
discard) leftover changes, branches and unpushed commits, a clean default
branch, and a branch of its own (D3, #62). start_milestone cuts the
milestone's branch; finish_milestone commits only the work, pushes and
opens a PR that closes the issue, under an intent, adopting an open PR and
treating a closed one as the operator's answer (D4). Between runs the
loop watches each item's PR: operator comments and inline review notes
(#69) reach the item, a merge or close hands back to the driver. A review
fix is checked after it's pushed and goes out as a new PR if the PR merged
first (D5). At boot an interrupted publish is settled against Gitea (L8).

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

nisse-dev/src/nisse_dev/loop/build.py

@@ -18,6 +18,7 @@ from nisse_dev.config import AgentConfig
 from nisse_dev.gitea import GiteaClient
 from nisse_dev.loop.agent import LoopAgent
 from nisse_dev.loop.driver import Driver
+from nisse_dev.loop.milestones import Milestones
 from nisse_dev.matrix import MatrixTransport
 from nisse_dev.oplog import OpLog
 from nisse_dev.state import StateStore
@@ -76,7 +77,7 @@ def build_loop_agent(config: AgentConfig) -> RunningLoop:
     host = build_host(config)
     credential = push_credential(config)
     remote = remote_url(gitea, config.gitea_repo, credential)
-    prepare_workspace(host, config, account, remote, credential)
+    git = prepare_workspace(host, config, account, remote, credential)
     workspace = Workspace(
         host,
         config.workspace,
@@ -108,6 +109,15 @@ def build_loop_agent(config: AgentConfig) -> RunningLoop:
         cancel=cancel,
         oplog=oplog,
         roles=config.roles.pinned(),
+        milestones=Milestones(
+            store,
+            git,
+            gitea,
+            repo=config.gitea_repo,
+            remote=remote,
+            credential=credential,
+            base=config.base_branch,
+        ),
     )
     return RunningLoop(
         config=config,