feat(documents): Phase A schema + service skeletons

Adds Phase A data model deltas to documents/templates and the new
document_watchers table. Introduces createFromWizard/createFromUpload
stubs, getDocumentDetail aggregator, cancelDocument flow, signed-doc
email composer, reservation agreement context, and notifyDocumentEvent
fan-out. Validator update accepts new template formats with html-only
bodyHtml requirement. EOI cadence backfilled to 1 day to preserve
current effective behaviour.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/db/migrations/meta/_journal.json

@@ -92,6 +92,13 @@
       "when": 1777308900666,
       "tag": "0012_large_zarda",
       "breakpoints": true
+    },
+    {
+      "idx": 13,
+      "version": "7",
+      "when": 1777334766194,
+      "tag": "0013_abnormal_thundra",
+      "breakpoints": true
     }
   ]
 }