Add issue identifiers, activity run tracking, and migration inspection

Add issuePrefix/issueCounter to companies and issueNumber/identifier to issues
for human-readable issue IDs (e.g. PAP-42). Add runId to activity_log for
linking activity to heartbeat runs. Rework DB client to support migration
state inspection and interactive pending migration prompts at startup.
Add reopen option to issue comments validator.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -22,6 +22,20 @@
       "when": 1771349403162,
       "tag": "0002_big_zaladane",
       "breakpoints": true
+    },
+    {
+      "idx": 3,
+      "version": "7",
+      "when": 1771456737635,
+      "tag": "0003_shallow_quentin_quire",
+      "breakpoints": true
+    },
+    {
+      "idx": 4,
+      "version": "7",
+      "when": 1771545600000,
+      "tag": "0004_issue_identifiers",
+      "breakpoints": true
     }
   ]
 }