feat: add webhook delivery detail

[giscebot]

Summary

• retain each verified webhook JSON payload for the configured receipt retention window
• add an admin-only delivery detail endpoint with payload hash and linked/coalesced job status
• add shareable delivery detail UI with navigation to the hook and generated job
• document retention and legacy deliveries without stored payloads

Validation

• pytest -q — 417 passed
• npm test — 64 passed
• npm run build

Refs #191

Requested by: @ecarreras

[ecarreras]

@giscebot resol conflictes

[giscebot]

Conflictes resolts al commit 09c0c3e, integrant origin/main sense reescriure la branca.

La resolució conserva el payload/detall de delivery i incorpora els nous camps enqueue_status/job_id; també corregeix la consulta del detall perquè retorni el job enllaçat o coalescit. He regenerat els assets del dashboard.

Validació local: 417 tests Python i 64 tests del dashboard; build del dashboard correcte. Els tres checks de CI del commit estan verds i GitHub marca la PR com a mergeable.

[pilipilisbot]

Reviewed the webhook delivery detail changes end to end: schema/backfill path, payload retention, admin-only API detail endpoint, linked/coalesced job lookup, dashboard routing/detail view, docs, and the conflict-resolution commit.

I did not find blocking issues. The implementation keeps the detail endpoint behind dashboard admin auth, preserves legacy rows with payload: null, and the schema migration covers existing webhook_shadow_receipts tables.

Validation checked:

• python3 -m compileall -q src tests
• git diff --check
• GitHub checks are green: dashboard, pytest 3.11, pytest 3.12

Local pytest/Vitest execution was not available in this worktree because the local environment does not have pytest/vitest installed, so I relied on the passing CI for the full test suites.

[giscebot]

Troballa operativa post-merge: l’esdeveniment de merge event-32530539283 s’ha despatxat com reply_comment / review_only, tot i que reproduint el mateix merge amb el parser actual retorna sync_after_merge. Això apunta a un desajust en la normalització o el transport de l’esdeveniment, no al diff de detall de deliveries d’aquesta PR.

No he fet cap canvi de branca ni metadata (revisió només). La PR ja estava aprovada, els tres checks eren verds i el merge és 758e81f.