feat(backfill): synthetic PR rows for pre-mirror GitHub PRs #68 (Alex) + #88 (Cameron)

Two historical GitHub PRs merged before our sync-mirror.sh tracked github_pr:
  - GitHub PR #68: alexastrum, 6 claims, merged Mar 9 2026 via squash merge
  - GitHub PR #88: Cameron-S1, 1 claim, merged early April

Their claim files were lost during a Forgejo→GitHub mirror overwrite and later
recovered via direct-to-main commits (dba00a79, da64f805). Because the
recovery commits bypassed the pipeline, our 'prs' table has no row to attach
originator events to — all 4 backfill-events.py strategies returned None,
leaving Alex + Cameron at 0 originator credits despite real historical work.

This reconstructs synthetic 'prs' rows so the existing github_pr strategy in
backfill-events.py attaches 7 originator events on re-run:
  - Numbers 900068 / 900088 live in a clearly-synthetic range that cannot
    collide with real Forgejo PRs (current max: 3941)
  - github_pr=68/88 wires up the existing lookup strategy
  - submitted_by=alexastrum / cameron-s1 establishes author attribution
  - merged_at from the recovery commit messages (not recovery-commit time)
  - last_error tags the rows as synthetic for future audits

Idempotent: INSERT OR IGNORE via check on number OR github_pr. Safe to replay.
Reversible: DELETE FROM prs WHERE number IN (900068, 900088).

After applying this script:
  python3 ops/backfill-events.py
will credit Alex with 6 author + 6 originator events (author=1.80, originator=0.90)
and Cameron with 1 author + 1 originator (0.30 + 0.15), all dated to the
historical merge dates — so 7d/30d leaderboard windows show them correctly.

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

scripts/backfill-synthetic-recovery-prs.py

@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+"""Reconstruct synthetic `prs` rows for historical GitHub PRs lost pre-mirror-wiring.
+
+Two PRs merged on GitHub before our sync-mirror.sh tracked `github_pr`:
+  - GitHub PR #68: alexastrum — 6 claims, merged 2026-03-09 via GitHub squash,
+    recovered to Forgejo via commit dba00a79 (Apr 16, after mirror erased files)
+  - GitHub PR #88: Cameron-S1 — 1 claim, recovered via commit da64f805
+
+The recovery commits wrote the files directly to main, so our `prs` table has
+no row to attach originator events to — the backfill-events.py strategies all
+return NULL. We reconstruct one synthetic `prs` row per historical GitHub PR so
+the events pipeline (and `github_pr` strategy in backfill-events) can credit
+Alex and Cameron properly.
+
+Numbers 900000+ are clearly synthetic and won't collide with real Forgejo PRs.
+
+Idempotent via INSERT OR IGNORE.
+
+Usage:
+  python3 scripts/backfill-synthetic-recovery-prs.py --dry-run
+  python3 scripts/backfill-synthetic-recovery-prs.py
+"""
+import argparse
+import os
+import sqlite3
+import sys
+from pathlib import Path
+
+DB_PATH = os.environ.get("PIPELINE_DB", "/opt/teleo-eval/pipeline/pipeline.db")
+
+# Historical GitHub PRs recovered via direct-to-main commits.
+# Original GitHub merge dates come from the recovery commit messages.
+RECOVERY_PRS = [
+    {
+        "number": 900068,
+        "github_pr": 68,
+        "branch": "gh-pr-68",
+        "status": "merged",
+        "domain": "ai-alignment",
+        "commit_type": "knowledge",
+        "tier": "STANDARD",
+        "leo_verdict": "approve",
+        "domain_verdict": "approve",
+        "submitted_by": "alexastrum",
+        "source_channel": "github",
+        "description": "Multi-agent git workflows production maturity | Cryptographic agent trust ratings | Defense in depth for AI agent oversight | Deterministic policy engines below LLM layer | Knowledge validation four-layer architecture | Structurally separating proposer and reviewer agents",
+        "merged_at": "2026-03-09 00:00:00",
+        "created_at": "2026-03-08 00:00:00",
+        "last_error": "synthetic_recovery: GitHub PR #68 pre-mirror-wiring reconstruction (commit dba00a79)",
+    },
+    {
+        "number": 900088,
+        "github_pr": 88,
+        "branch": "gh-pr-88",
+        "status": "merged",
+        "domain": "ai-alignment",
+        "commit_type": "knowledge",
+        "tier": "STANDARD",
+        "leo_verdict": "approve",
+        "domain_verdict": "approve",
+        "submitted_by": "cameron-s1",
+        "source_channel": "github",
+        "description": "Orthogonality is an artefact of specification architectures not a property of intelligence itself",
+        "merged_at": "2026-04-01 00:00:00",
+        "created_at": "2026-04-01 00:00:00",
+        "last_error": "synthetic_recovery: GitHub PR #88 pre-mirror-wiring reconstruction (commit da64f805)",
+    },
+]
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--dry-run", action="store_true")
+    args = parser.parse_args()
+
+    if not Path(DB_PATH).exists():
+        print(f"ERROR: DB not found at {DB_PATH}", file=sys.stderr)
+        sys.exit(1)
+
+    conn = sqlite3.connect(DB_PATH, timeout=30)
+    conn.row_factory = sqlite3.Row
+
+    # Guard against colliding with real PRs — current max + some headroom.
+    max_real = conn.execute(
+        "SELECT MAX(number) FROM prs WHERE number < 900000"
+    ).fetchone()[0] or 0
+    print(f"Max real Forgejo PR number: {max_real}")
+    if max_real >= 900000:
+        print(f"ERROR: real PR numbers reached synthetic range (>= 900000). Aborting.",
+              file=sys.stderr)
+        sys.exit(2)
+
+    inserted = 0
+    skipped = 0
+    for row in RECOVERY_PRS:
+        existing = conn.execute(
+            "SELECT number FROM prs WHERE number = ? OR github_pr = ?",
+            (row["number"], row["github_pr"]),
+        ).fetchone()
+        if existing:
+            print(f"  PR #{row['number']} (github_pr={row['github_pr']}): already exists — skip")
+            skipped += 1
+            continue
+        print(f"  {'(dry-run) ' if args.dry_run else ''}INSERT synthetic PR #{row['number']} "
+              f"(github_pr={row['github_pr']}, submitted_by={row['submitted_by']}, "
+              f"merged_at={row['merged_at']})")
+        if not args.dry_run:
+            conn.execute(
+                """INSERT INTO prs (
+                    number, github_pr, branch, status, domain, commit_type, tier,
+                    leo_verdict, domain_verdict, submitted_by, source_channel,
+                    description, merged_at, created_at, last_error
+                ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)""",
+                (
+                    row["number"], row["github_pr"], row["branch"], row["status"],
+                    row["domain"], row["commit_type"], row["tier"],
+                    row["leo_verdict"], row["domain_verdict"],
+                    row["submitted_by"], row["source_channel"],
+                    row["description"], row["merged_at"], row["created_at"],
+                    row["last_error"],
+                ),
+            )
+            inserted += 1
+
+    if not args.dry_run:
+        conn.commit()
+
+    print(f"\nInserted {inserted}, skipped {skipped}")
+    if not args.dry_run and inserted:
+        print("\nNext step: re-run backfill-events.py to attach originator events")
+        print("  python3 ops/backfill-events.py")
+
+
+if __name__ == "__main__":
+    main()