FN-8403: extract automation and plugin route registrars

Move automation and plugin HTTP handlers out of the routes aggregator into focused domain modules.

- Extract live automation streaming and step-execution helpers
- Register automation, routine, webhook, and plugin handlers through the domain registrar
- Document plugin route ordering and update modular-route baselines

Files changed:
 packages/dashboard/src/routes.ts                   | 2779 ++------------------
 packages/dashboard/src/routes/README.md            |    3 +-
 .../dashboard/src/routes/automation-live-run.ts    |  322 +++
 .../src/routes/automation-step-execution.ts        |  445 ++++
 .../src/routes/plugin-bundled-runtimes.ts          |   88 +
 .../src/routes/register-plugins-automation.ts      | 1540 ++++++++++-
 scripts/lib/routes-modular-baseline.json           |    2 +-
 scripts/line-count-baseline.json                   |    2 +-
 8 files changed, 2604 insertions(+), 2577 deletions(-)

Fusion-Task-Id: FN-8403

Fusion-Task-Lineage: 2072d39b-6335-4163-a56a-7d418edc9095

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

scripts/lib/routes-modular-baseline.json

@@ -1,3 +1,3 @@
 {
-  "inlineRouteRegistrations": 79
+  "inlineRouteRegistrations": 42
 }

scripts/line-count-baseline.json

@@ -73,7 +73,7 @@
   "packages/dashboard/src/github.ts": 4984,
   "packages/dashboard/src/mission-routes.ts": 3909,
   "packages/dashboard/src/planning.ts": 3322,
-  "packages/dashboard/src/routes.ts": 5629,
+  "packages/dashboard/src/routes.ts": 3272,
   "packages/dashboard/src/routes/register-git-github.ts": 6342,
   "packages/dashboard/src/routes/register-settings-memory-routes.ts": 2403,
   "packages/dashboard/src/routes/register-task-workflow-routes.ts": 5530,