feat(scm): wire observer messenger + RepoOriginURL + persist dedup (#108)

[harshitsinghbhandari]

Summary

Closes the SCM-observer end-to-end nudge path called out in #108 by landing all three wiring fixes in one PR. Without these three pieces stacked together the observer runs and persists but never reaches the agent.

1) Thread the runtime messenger into the Lifecycle Manager

startLifecycle used to construct the LCM with a nil messenger, so every SCM-driven nudge dropped silently inside sendOnce (backend/internal/lifecycle/reactions.go). Built newSessionMessenger before startLifecycle in daemon.go and added messenger ports.AgentMessenger to the startLifecycle signature so the wired messenger reaches lifecycle.New. Closes the "Daemon constructs LCM with a real messenger (no nil at lifecycle_wiring.go)" acceptance item.

2) Populate RepoOriginURL at project add + lazy observer backfill

project.Service.Add now shells out to git -C path remote get-url origin and assigns the trimmed URL onto the row. A missing/erroring git invocation logs INFO and falls back to "" so ao project add never fails on a remoteless or non-git path. To cover already-registered projects, the SCM observer's discoverSubjects lazily backfills RepoOriginURL via the same shell-out and persists it back through UpsertProject, so subsequent polls skip the fork-exec. Implements Option A from the issue. Closes the "populates RepoOriginURL" and "backfilled lazily" acceptance items.

3) Persist reaction-dedup signatures across restart

Added migration 0005_pr_last_nudge_signature.sql (ALTER TABLE pr ADD COLUMN last_nudge_signature TEXT NOT NULL DEFAULT '') plus two scoped sqlc queries (GetPRLastNudgeSignature, UpdatePRLastNudgeSignature). lifecycle.Manager.sendOnce now loads the JSON payload ({"seen":{…},"attempts":{…}}) on first touch of each PR and persists after every successful send, so a bouncing daemon stops re-nudging the agent for still-failing CI / unresolved review threads on the first post-restart poll. Closes the "pr.last_nudge_signature column exists; sendOnce consults + updates it" acceptance item.

Test plan

• cd backend && go build ./... — clean
• cd backend && go test -race ./... — clean except TestSessionStreamsRealZellijPane (zellij UNIX-socket path > macOS 103-byte limit; pre-existing on main, unrelated to this PR — verified by stashing changes and re-running)
• New unit tests:
  • TestWiring_StartLifecycleThreadsMessengerIntoLCM — wires real LCM with a captureMessenger, drives an SCM observation, asserts the messenger is invoked
  • TestManager_AddPopulatesRepoOriginURL — table-driven: git repo with origin → populated; git repo without origin → empty
  • TestDiscoverSubjects_BackfillsRepoOriginURL / TestDiscoverSubjects_NonGitPathDoesNotBackfill — lazy backfill happy path + non-git fallback
  • TestPRObservation_DedupSurvivesManagerRestart — same signature suppressed across a fresh Manager over the same store; genuinely new signature still fires
  • TestPRObservation_DedupPersistsAcrossPRs — payloads keyed per-PR, not collated
• Validation gate: agent-ci was skipped — Docker isn't available locally and the orchestrator confirmed GitHub Actions is the authoritative pre-merge gate for this repo. Local go build + go test -race is clean.

Notes

• sqlc isn't installed locally; the two new queries were appended to internal/storage/sqlite/gen/pr.sql.go by hand in the existing sqlc style. The existing gen.PR struct wasn't touched (no SELECT *; existing queries enumerate columns explicitly), so adding the column is non-breaking for unrelated code paths.
• The dedup payload is opaque to storage; lifecycle owns the JSON schema. Corrupt payloads degrade to "empty" (one extra nudge) rather than crashing the lifecycle write path.

Closes #108

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR completes the SCM-observer end-to-end nudge path by landing three wiring fixes: threading the runtime messenger into the Lifecycle Manager, populating RepoOriginURL at project registration with lazy backfill in the SCM observer, and persisting per-PR reaction-dedup signatures across daemon restarts via a new last_nudge_signature column.

• Messenger wiring: startLifecycle now receives the pre-built messenger so lifecycle.New is constructed with a real messenger instead of nil, closing the silent-drop path in sendOnce.
• RepoOriginURL population: project.Service.Add shells out to git remote get-url origin; the SCM observer's discoverSubjects lazily backfills existing projects with best-effort semantics.
• Dedup persistence: A new migration adds last_nudge_signature TEXT NOT NULL DEFAULT ''; sendOnce lazily loads the per-PR JSON payload on first touch and writes it back after each successful send.

Confidence Score: 5/5

Safe to merge — all three wiring fixes are correct, the ordering invariant (WriteSCMObservation before ApplySCMObservation) is clearly maintained in the observer, and the new dedup persistence degrades gracefully under failure.

The messenger wiring, RepoOriginURL population, and dedup-persistence changes are all well-scoped and independently tested. The one non-obvious assumption — that the pr row always exists when UpdatePRLastNudgeSignature is called — is guaranteed by the observer's write-before-notify ordering and is clearly documented. No data-loss or incorrect-state paths were found.

No files require special attention; the hand-written sqlc functions in gen/pr.sql.go match the existing style and the SQL parameter ordering is correct.

Important Files Changed

Filename	Overview
backend/internal/lifecycle/reactions.go	Adds prURL parameter to sendOnce, lazy DB load via loadPRSignaturesLocked, and post-send persist via persistPRSignaturesLocked. The reactionKeyTargetsPR helper correctly handles HTTPS PR URLs with SplitN(key,":",2). The mutex is held throughout the DB I/O and the messenger Send call — pre-existing pattern, not a regression.
backend/internal/daemon/daemon.go	Moves newSessionMessenger before startLifecycle and threads it through the signature; straightforward ordering fix, no logic changes.
backend/internal/observe/scm/observer.go	Adds UpsertProject to the Store interface and backfills RepoOriginURL in discoverSubjects. The in-memory cache is per-call, so a failed upsert only affects the current tick; the next tick retries from the DB.
backend/internal/storage/sqlite/store/pr_store.go	Adds GetPRLastNudgeSignature (with sql.ErrNoRows → "" mapping) and UpdatePRLastNudgeSignature. The update is a plain SQL UPDATE; 0 rows affected is silently ignored, relying on the observer always having written the PR row first.
backend/internal/storage/sqlite/gen/pr.sql.go	Hand-written sqlc-style functions for GetPRLastNudgeSignature and UpdatePRLastNudgeSignature. Parameter order and SQL placeholders are correct; ExecContext result is discarded, matching existing sqlc :exec style.
backend/internal/storage/sqlite/migrations/0005_pr_last_nudge_signature.sql	Adds last_nudge_signature TEXT NOT NULL DEFAULT '' with goose Up/Down; the DEFAULT '' ensures existing rows are non-null, consistent with the store's empty-string semantics.

Sequence Diagram

sequenceDiagram
    participant Observer as SCM Observer
    participant Store as SQLite Store
    participant LCM as Lifecycle Manager
    participant Messenger as Session Messenger

    Observer->>Store: WriteSCMObservation(pr, checks, ...)
    Store-->>Observer: ok (pr row now exists)

    Observer->>LCM: ApplySCMObservation(sessionID, obs)
    LCM->>LCM: scmToPRObservation(obs)
    LCM->>LCM: sendOnce(prURL, key, sig, msg)

    alt First touch of prURL this process
        LCM->>Store: GetPRLastNudgeSignature(prURL)
        Store-->>LCM: empty or JSON payload
        LCM->>LCM: merge into react.seen / react.attempts
    end

    alt sig not in seen (new nudge)
        LCM->>Messenger: Send(sessionID, msg)
        Messenger-->>LCM: ok
        LCM->>LCM: update react.seen[key], react.attempts[key]
        LCM->>Store: UpdatePRLastNudgeSignature(prURL, JSON)
        Store-->>LCM: ok
    end

    LCM-->>Observer: ok
    Observer->>Store: WriteSCMObservation(finalPR, ...) [ack hashes]

Loading

_{Reviews (2): Last reviewed commit: "fix: silence nilerr, address reviewer no..." | Re-trigger Greptile}