feat: add fundamentals parity reporting

docs/fundamentals-deployment.md

@@ -8,6 +8,7 @@ approval. Do not add OS cron entries: the application scheduler owns both jobs.
 
 - `Dolt Earnings Import (shadow)` runs daily at 02:30 America/New_York.
 - `SEC Fundamentals Import (shadow)` runs daily at 04:00 America/New_York.
+- `Fundamentals Parity Report (read-only)` runs daily at 05:30 America/New_York.
 - Both jobs are visible, toggleable, and manually triggerable in Admin → Jobs.
 - Cron expressions are editable in Admin → Schedule.
 - Every attempt is recorded in `data_import_runs`; failures also create a system
@@ -28,11 +29,14 @@ DOLT_EARNINGS_SUBDIR=earnings
 DOLT_MIN_FREE_DISK_GB=5.0
 SEC_USER_AGENT=signal-platform/1.0 (contact: real-address@example.com)
 SEC_REQUEST_SPACING_SECONDS=0.2
+FUNDAMENTALS_PARITY_REPORT_DIR=/var/lib/signal-platform/reports/fundamentals-parity
 ```
 
 Use a real monitored contact address. Keep at least 5 GB free at the Dolt data
 path; 8–10 GB gives comfortable growth headroom. The data directory must stay
 outside `/opt/signalplatform`, because deployments use `rsync --delete` there.
+The parity-report directory is also persistent and owned by the service user;
+its small timestamped JSON/CSV bundles form the temporary A5 review trail.
 
 ## One-time provisioning
 
@@ -79,6 +83,28 @@ In Admin → Jobs, wait until no other job is running, then:
 5. Open several ticker pages and confirm the fundamentals panel has populated
    data and still handles partial/missing issuers cleanly.
 
+## A5 parity observation window
+
+After both shadow imports are healthy, trigger **Fundamentals Parity Report
+(read-only)** once in Admin → Jobs. The **A5 Fundamentals Parity** card above
+the jobs shows the latest coverage/delta summary and provides authenticated JSON
+and CSV downloads. The canonical server-side bundles are archived at:
+
+```text
+/var/lib/signal-platform/reports/fundamentals-parity/
+```
+
+The scheduler then generates one report daily at 05:30 New York time, after the
+02:30 Dolt and 04:00 SEC jobs. Review 5–7 consecutive reports before making the
+cutover decision. A report never writes `fundamental_data`, dimension/composite
+scores, rankings, qualification state, or an approval flag. Materiality bands
+only highlight rows for review; A5 still requires explicit approval.
+
+Each bundle contains legacy and candidate P/E, revenue growth, and earnings
+surprise; definition notes; source revisions and price dates; recomputed legacy
+and candidate fundamental scores; and per-universe fundamental-rank changes.
+Definition changes remain explicit even when numeric deltas are small.
+
 Optional database verification:
 
 ```sql
@@ -141,3 +167,6 @@ locks. A second Admin trigger should independently report the job as busy.
   audit rows) must remain covered by the normal production database backup.
 - Do not proceed to A5 while either shadow feed is unhealthy or the parity gate
   has not received explicit approval.
+- If report generation fails, inspect Admin → System Events and verify
+  `FUNDAMENTALS_PARITY_REPORT_DIR` exists and is writable by `deploy`. Existing
+  reports and all live data remain untouched.