feat: add pushedAt field (R5/R13) — pipe GitHub pushed_at through all layers

- V18 migration: add pushed_at_gh TIMESTAMPTZ column to repos
- Expose pushedAt in RepoResponse (distinct from updatedAt/metadata change)
- Persist in GitHubSearchClient ingest, upsertMetadataOnly, and Meili sync
- Map in RepoRepository, SearchRepository, MeiliRepoHit, all route mappers
- Add POST /internal/backfill-pushed-at to fill NULL rows on existing data

Co-Authored-By: Oz <oz-agent@warp.dev>

Author: rainxchzed

src/main/kotlin/zed/rainxch/githubstore/db/DatabaseFactory.kt

@@ -96,6 +96,7 @@ object DatabaseFactory {
             "V15__license_info.sql",
             "V16__oauth_ephemeral.sql",
             "V17__signing_fingerprint_host.sql",
+            "V18__pushed_at.sql",
         )
         for (migration in migrations) {
             val rawSql = this::class.java.classLoader

src/main/kotlin/zed/rainxch/githubstore/db/MeilisearchClient.kt

@@ -152,6 +152,8 @@ data class MeiliRepoHit(
     val has_installers_linux: Boolean = false,
     val trending_score: Double? = null,
     val popularity_score: Double? = null,
+    // R5/R13: last commit timestamp; piped from GitHub pushed_at.
+    val pushed_at: String? = null,
     // Must be populated on every addDocuments() call — Meili's POST /documents
     // *replaces* the doc, so omitting this field wipes the SignalAggregationWorker's
     // most recent score. Null here is "no signal yet," not "no longer ranked."

src/main/kotlin/zed/rainxch/githubstore/db/RepoRepository.kt

@@ -95,6 +95,7 @@ class RepoRepository {
             releasesUrl = "${this[Repos.htmlUrl]}/releases",
             updatedAt = this[Repos.updatedAtGh]?.toString(),
             createdAt = this[Repos.createdAtGh]?.toString(),
+            pushedAt = this[Repos.pushedAtGh]?.toString(),
             latestReleaseDate = releaseDateStr,
             latestReleaseTag = this[Repos.latestReleaseTag],
             releaseRecency = recencyDays,

src/main/kotlin/zed/rainxch/githubstore/db/SearchRepository.kt

@@ -55,7 +55,7 @@ class SearchRepository {
                        has_installers_android, has_installers_windows,
                        has_installers_macos, has_installers_linux,
                        trending_score, popularity_score, search_score,
-                       updated_at_gh, created_at_gh
+                       updated_at_gh, created_at_gh, pushed_at_gh
                 FROM repos
                 """.trimIndent()
             )
@@ -115,6 +115,7 @@ class SearchRepository {
                             releasesUrl = "${rs.getString("html_url")}/releases",
                             updatedAt = rs.getString("updated_at_gh"),
                             createdAt = rs.getString("created_at_gh"),
+                            pushedAt = rs.getString("pushed_at_gh"),
                             latestReleaseDate = releaseDateStr,
                             latestReleaseTag = rs.getString("latest_release_tag"),
                             releaseRecency = recencyDays,

src/main/kotlin/zed/rainxch/githubstore/db/Tables.kt

@@ -36,6 +36,9 @@ object Repos : Table("repos") {
     val searchScore = float("search_score").nullable()
     val createdAtGh = timestampWithTimeZone("created_at_gh").nullable()
     val updatedAtGh = timestampWithTimeZone("updated_at_gh").nullable()
+    // R5/R13: last default-branch commit (GitHub pushed_at), distinct from
+    // updatedAtGh (last metadata change). Used by client Heartbeat animation.
+    val pushedAtGh = timestampWithTimeZone("pushed_at_gh").nullable()
     val indexedAt = timestampWithTimeZone("indexed_at")
 
     override val primaryKey = PrimaryKey(id)

src/main/kotlin/zed/rainxch/githubstore/ingest/GitHubSearchClient.kt

@@ -539,6 +539,9 @@ class GitHubSearchClient(
                     it[hasInstallersLinux] = platforms["linux"] ?: false
                     it[downloadCount] = r.downloadCount
                     it[searchScore] = scoreToWrite
+                    it[pushedAtGh] = repo.pushedAt?.let {
+                        try { OffsetDateTime.parse(it) } catch (_: Exception) { null }
+                    }
                     it[indexedAt] = OffsetDateTime.now()
                 }
                 scoredByRepoId[repo.id] = scoreToWrite.toDouble()
@@ -576,6 +579,7 @@ class GitHubSearchClient(
                     has_installers_windows = r.platformFlags["windows"] ?: false,
                     has_installers_macos = r.platformFlags["macos"] ?: false,
                     has_installers_linux = r.platformFlags["linux"] ?: false,
+                    pushed_at = r.repo.pushedAt,
                     // Meili's POST /documents replaces the whole doc. Omitting this
                     // would wipe the SignalAggregationWorker's most recent score
                     // on every passthrough/refresh until the next hourly cycle.
@@ -622,6 +626,7 @@ class GitHubSearchClient(
                 releasesUrl = "${repo.htmlUrl}/releases",
                 updatedAt = repo.updatedAt,
                 createdAt = repo.createdAt,
+                pushedAt = repo.pushedAt,
                 latestReleaseDate = releaseDateStr,
                 latestReleaseTag = release.tagName,
                 releaseRecency = recencyDays,
@@ -682,6 +687,8 @@ data class GitHubRepo(
     val disabled: Boolean = false,
     @SerialName("updated_at") val updatedAt: String? = null,
     @SerialName("created_at") val createdAt: String? = null,
+    // R5/R13: last default-branch commit, distinct from updated_at (metadata change).
+    @SerialName("pushed_at") val pushedAt: String? = null,
 )
 
 @Serializable

src/main/kotlin/zed/rainxch/githubstore/model/RepoResponse.kt

@@ -49,6 +49,10 @@ data class RepoResponse(
     val releasesUrl: String?,
     val updatedAt: String?,
     val createdAt: String?,
+    // R5/R13: last commit timestamp (GitHub pushed_at = default-branch HEAD).
+    // Distinct from updatedAt (last metadata change). Null for Meili-served
+    // search results until meili_sync.py backfills the field.
+    val pushedAt: String? = null,
     val latestReleaseDate: String? = null,
     val latestReleaseTag: String? = null,
     val releaseRecency: Int? = null,

src/main/kotlin/zed/rainxch/githubstore/routes/InternalRoutes.kt

@@ -16,6 +16,7 @@ import kotlinx.coroutines.launch
 import kotlinx.serialization.Serializable
 import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
 import org.jetbrains.exposed.sql.SqlExpressionBuilder.isNull
+import java.time.OffsetDateTime
 import org.jetbrains.exposed.sql.selectAll
 import org.jetbrains.exposed.sql.transactions.TransactionManager
 import org.jetbrains.exposed.sql.transactions.experimental.newSuspendedTransaction
@@ -160,6 +161,54 @@ fun Route.internalRoutes(
             )
         }
 
+        // One-shot backfill for pushed_at_gh (V18). Iterates every repo
+        // where pushed_at_gh IS NULL, re-fetches from GitHub, and writes
+        // the field. Self-terminates once all rows are filled. Shares the
+        // same backfillRunning gate as /backfill-stale so the two never
+        // run concurrently and don't race the rotation pool.
+        post("/backfill-pushed-at") {
+            if (!authorized(call, adminToken)) {
+                return@post respondNotFound(call)
+            }
+            val limit = call.request.queryParameters["limit"]
+                ?.toIntOrNull()
+                ?.coerceIn(1, 10_000)
+                ?: 10_000
+            if (!backfillRunning.compareAndSet(false, true)) {
+                call.response.header(HttpHeaders.RetryAfter, "60")
+                return@post call.respond(
+                    HttpStatusCode.Conflict,
+                    BackfillResponse(scheduled = 0, started = false, message = "backfill_already_running"),
+                )
+            }
+            val candidates = transaction {
+                Repos.selectAll()
+                    .where { Repos.pushedAtGh.isNull() }
+                    .orderBy(Repos.id)
+                    .limit(limit)
+                    .map { it[Repos.id] to it[Repos.fullName] }
+            }
+            if (candidates.isEmpty()) {
+                backfillRunning.set(false)
+                return@post call.respond(
+                    HttpStatusCode.OK,
+                    BackfillResponse(scheduled = 0, started = false, message = "no rows missing pushed_at"),
+                )
+            }
+            backfillScope.launch {
+                try {
+                    runBackfill(searchClient, candidates)
+                } finally {
+                    backfillRunning.set(false)
+                }
+            }
+            call.response.header(HttpHeaders.CacheControl, "no-store")
+            call.respond(
+                HttpStatusCode.Accepted,
+                BackfillResponse(scheduled = candidates.size, started = true),
+            )
+        }
+
         // Browser dashboard. Basic Auth required in prod so the browser prompts
         // for credentials on first visit; optional in dev for local inspection.
         authenticate(ADMIN_BASIC_AUTH, optional = adminToken == null) {
@@ -259,7 +308,10 @@ private fun upsertMetadataOnly(repo: GitHubRepo) {
             it[licenseSpdxId] = repo.license?.spdxId
             it[licenseName] = repo.license?.name
             it[description] = repo.description
-            it[indexedAt] = java.time.OffsetDateTime.now()
+            it[pushedAtGh] = repo.pushedAt?.let { raw ->
+                try { OffsetDateTime.parse(raw) } catch (_: Exception) { null }
+            }
+            it[indexedAt] = OffsetDateTime.now()
         }
     }
 }

src/main/kotlin/zed/rainxch/githubstore/routes/RepoRoutes.kt

@@ -143,4 +143,5 @@ internal fun GitHubRepo.toMetadataOnlyResponse(): RepoResponse = RepoResponse(
     releasesUrl = "$htmlUrl/releases",
     updatedAt = updatedAt,
     createdAt = createdAt,
+    pushedAt = pushedAt,
 )

src/main/kotlin/zed/rainxch/githubstore/routes/SearchRoutes.kt

@@ -292,6 +292,7 @@ private fun zed.rainxch.githubstore.db.MeiliRepoHit.toRepoResponse() = RepoRespo
     releasesUrl = "$html_url/releases",
     updatedAt = null,
     createdAt = null,
+    pushedAt = pushed_at,
     latestReleaseDate = latest_release_date,
     latestReleaseTag = latest_release_tag,
     downloadCount = download_count,