docs: refresh for the dashboard rework + recent harness commits

- web-ui.md: side panel, approval card + 3-way diff base, stats
  page, forge config links, removed agent.nix viewer, per-agent
  loose-ends inline answer.
- approvals.md: forge mirror section + diff base toggle.
- turn-loop.md: recv(max), get_logs, remind, loose-ends, whoami.
- agent.md / manager.md prompts: recv(max), remind, get_logs.
- CLAUDE.md: forge.rs / stats.rs / hive-forge.nix in the file
  map, scratchpad refresh.

also: forgejo migrations.ALLOW_LOCALNETWORKS = true so an in-hive
mirror of the hyperhive repo can import from a localhost source.

nix/modules/hive-forge.nix

@@ -137,6 +137,13 @@ in
                 DEFAULT_BRANCH = "main";
                 DEFAULT_PRIVATE = "private";
               };
+              # Repo migrations / pull-mirrors fetch from the source
+              # URL *inside* Forgejo. hyperhive code is synced from
+              # `localhost` (and the host LAN), which Forgejo's
+              # migration guard blocks by default ("cannot import from
+              # disallowed hosts"). Allow loopback + RFC-1918 sources
+              # so an in-hive mirror of the hyperhive repo works.
+              migrations.ALLOW_LOCALNETWORKS = true;
               log.LEVEL = "Warn";
               # F3 (federation) computes its data dir relative to the
               # forgejo binary, which lands in the read-only nix