Tier 3 skip detection: audio fingerprinting, prototyped and built

Closes the last deferred Phase 2 item. Desktop-prototyped first, per the
design plan's own instruction, against three real shows (see the prototype
findings recorded in memory): NPR Up First (a clean ~6s intro sting, r
0.96-0.998 across every pair tested), Tangle (a long 60-90s open/sponsor
read, equally reliable), and Darknet Diaries (no real intro -- a segment
that matched between two temporally-close episodes turned out to be a
dynamically-inserted ad, confirmed by checking a 2018 episode that matched
the same "intro" despite the multi-year gap).

That last finding drove the actual design: IntroOutroDetector requires 3+
independently-fetched episodes to agree before trusting a candidate and
auto-applying it, which is exactly what the Darknet Diaries ad would not
have survived. The confirmation threshold is the safety mechanism, not
just caution for its own sake -- and it's now a parameter, not a hardcoded
assumption, after coverage review found the "still tentative" branch was
unreachable at the original threshold.

- AudioCorrelation: FFT-based normalized cross-correlation, a Kotlin port
  of the validated prototype. Tested against numpy/scipy-derived ground
  truth fixtures, not just self-consistency -- the prototype's own
  normalization bug (global mean instead of each window's local mean,
  producing a bogus 0.98 "match" plain correlation put at -0.02) is exactly
  what that guards against being ported here unnoticed.
- IntroOutroDetector: the pure state machine (waiting/tentative/confirmed/
  discard-on-mismatch), mirroring DripSchedule's shape.
- MediaCodecClipSource: the one Android-only piece (MediaExtractor/
  MediaCodec decode to mono 8kHz PCM), on the framework-adapter coverage
  exclusion list for the same reason PlayerConnection is.
- Storage: AppDatabase 6->7, a new show_fingerprints table (one row per
  show per intro/outro, tracking the current candidate clip and how many
  episodes have confirmed it) and two new nullable EpisodeEntity columns.
  Tier 2's manual per-show offset remains the fallback -- PlaybackProgress
  itself is unchanged; DetectedSkip.kt is the entire integration surface.
- Trigger: EpisodeDownloader gained an onDownloaded hook (every download
  route ends up there, manual or queued) firing a new one-shot
  FingerprintWorker per episode.

Coverage improved (90.13% -> 91.70%): the new pure logic is fully tested,
and closing two real gaps the coverage review surfaced (an untested
first-two-episodes-disagree path, and ShowFingerprintEntity's hand-written
equals/hashCode, needed because a ByteArray property breaks the generated
one) accounted for more than the new Android-glue lines cost.

Not yet verified on a device -- no phone connected this session. The
MigrationTest 6->7 case and the actual decode/match pipeline both need a
real run before this is trusted with real playback.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Sj3CoWEedM56bebByKgNxA

1 files changed, 596 insertions, 0 deletions

diff --git a/app/schemas/org.terst.listen.data.AppDatabase/7.json b/app/schemas/org.terst.listen.data.AppDatabase/7.json
new file mode 100644
index 0000000..20b92c3
--- /dev/null
+++ b/app/schemas/org.terst.listen.data.AppDatabase/7.json
@@ -0,0 +1,596 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 7,
+    "identityHash": "564d893d23f7e7f14cb4afc1b65c83f0",
+    "entities": [
+      {
+        "tableName": "subscriptions",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` TEXT NOT NULL, `feedUrl` TEXT NOT NULL, `kind` TEXT NOT NULL, `title` TEXT NOT NULL, `description` TEXT, `author` TEXT, `imageUrl` TEXT, `link` TEXT, `addedAtMs` INTEGER NOT NULL, `etag` TEXT, `lastModified` TEXT, `lastFetchedAtMs` INTEGER, `lastError` TEXT, `playbackSpeed` REAL, `skipIntroMs` INTEGER NOT NULL, `skipOutroMs` INTEGER NOT NULL, `dripEnabled` INTEGER NOT NULL DEFAULT 0, `dripIntervalMs` INTEGER NOT NULL DEFAULT 86400000, `dripCount` INTEGER NOT NULL DEFAULT 1, `dripOldestFirst` INTEGER NOT NULL DEFAULT 1, `dripLastReleaseAtMs` INTEGER, `skipAdChapters` INTEGER NOT NULL DEFAULT 0, PRIMARY KEY(`id`))",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "feedUrl",
+            "columnName": "feedUrl",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "kind",
+            "columnName": "kind",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "title",
+            "columnName": "title",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "description",
+            "columnName": "description",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "author",
+            "columnName": "author",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "imageUrl",
+            "columnName": "imageUrl",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "link",
+            "columnName": "link",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "addedAtMs",
+            "columnName": "addedAtMs",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "etag",
+            "columnName": "etag",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "lastModified",
+            "columnName": "lastModified",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "lastFetchedAtMs",
+            "columnName": "lastFetchedAtMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "lastError",
+            "columnName": "lastError",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "playbackSpeed",
+            "columnName": "playbackSpeed",
+            "affinity": "REAL"
+          },
+          {
+            "fieldPath": "skipIntroMs",
+            "columnName": "skipIntroMs",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "skipOutroMs",
+            "columnName": "skipOutroMs",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "dripEnabled",
+            "columnName": "dripEnabled",
+            "affinity": "INTEGER",
+            "notNull": true,
+            "defaultValue": "0"
+          },
+          {
+            "fieldPath": "dripIntervalMs",
+            "columnName": "dripIntervalMs",
+            "affinity": "INTEGER",
+            "notNull": true,
+            "defaultValue": "86400000"
+          },
+          {
+            "fieldPath": "dripCount",
+            "columnName": "dripCount",
+            "affinity": "INTEGER",
+            "notNull": true,
+            "defaultValue": "1"
+          },
+          {
+            "fieldPath": "dripOldestFirst",
+            "columnName": "dripOldestFirst",
+            "affinity": "INTEGER",
+            "notNull": true,
+            "defaultValue": "1"
+          },
+          {
+            "fieldPath": "dripLastReleaseAtMs",
+            "columnName": "dripLastReleaseAtMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "skipAdChapters",
+            "columnName": "skipAdChapters",
+            "affinity": "INTEGER",
+            "notNull": true,
+            "defaultValue": "0"
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "id"
+          ]
+        },
+        "indices": [
+          {
+            "name": "index_subscriptions_feedUrl",
+            "unique": true,
+            "columnNames": [
+              "feedUrl"
+            ],
+            "orders": [],
+            "createSql": "CREATE UNIQUE INDEX IF NOT EXISTS `index_subscriptions_feedUrl` ON `${TABLE_NAME}` (`feedUrl`)"
+          }
+        ]
+      },
+      {
+        "tableName": "episodes",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` TEXT NOT NULL, `subscriptionId` TEXT NOT NULL, `guid` TEXT NOT NULL, `title` TEXT NOT NULL, `description` TEXT, `mediaUrl` TEXT NOT NULL, `mediaType` TEXT NOT NULL, `mediaLengthBytes` INTEGER, `durationMs` INTEGER, `publishedAtMs` INTEGER, `seasonNumber` INTEGER, `episodeNumber` INTEGER, `imageUrl` TEXT, `chaptersUrl` TEXT, `discoveredAtMs` INTEGER NOT NULL, `positionMs` INTEGER NOT NULL, `playedAtMs` INTEGER, `downloadState` TEXT NOT NULL, `localPath` TEXT, `downloadedAtMs` INTEGER, `dripReleasedAtMs` INTEGER, `appliedRuleId` TEXT, `appliedRuleReason` TEXT, `speedOverride` REAL, `chaptersJson` TEXT, `detectedIntroMs` INTEGER, `detectedOutroMs` INTEGER, PRIMARY KEY(`id`), FOREIGN KEY(`subscriptionId`) REFERENCES `subscriptions`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "subscriptionId",
+            "columnName": "subscriptionId",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "guid",
+            "columnName": "guid",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "title",
+            "columnName": "title",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "description",
+            "columnName": "description",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "mediaUrl",
+            "columnName": "mediaUrl",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "mediaType",
+            "columnName": "mediaType",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "mediaLengthBytes",
+            "columnName": "mediaLengthBytes",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "durationMs",
+            "columnName": "durationMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "publishedAtMs",
+            "columnName": "publishedAtMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "seasonNumber",
+            "columnName": "seasonNumber",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "episodeNumber",
+            "columnName": "episodeNumber",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "imageUrl",
+            "columnName": "imageUrl",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "chaptersUrl",
+            "columnName": "chaptersUrl",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "discoveredAtMs",
+            "columnName": "discoveredAtMs",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "positionMs",
+            "columnName": "positionMs",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "playedAtMs",
+            "columnName": "playedAtMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "downloadState",
+            "columnName": "downloadState",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "localPath",
+            "columnName": "localPath",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "downloadedAtMs",
+            "columnName": "downloadedAtMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "dripReleasedAtMs",
+            "columnName": "dripReleasedAtMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "appliedRuleId",
+            "columnName": "appliedRuleId",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "appliedRuleReason",
+            "columnName": "appliedRuleReason",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "speedOverride",
+            "columnName": "speedOverride",
+            "affinity": "REAL"
+          },
+          {
+            "fieldPath": "chaptersJson",
+            "columnName": "chaptersJson",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "detectedIntroMs",
+            "columnName": "detectedIntroMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "detectedOutroMs",
+            "columnName": "detectedOutroMs",
+            "affinity": "INTEGER"
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "id"
+          ]
+        },
+        "indices": [
+          {
+            "name": "index_episodes_subscriptionId",
+            "unique": false,
+            "columnNames": [
+              "subscriptionId"
+            ],
+            "orders": [],
+            "createSql": "CREATE INDEX IF NOT EXISTS `index_episodes_subscriptionId` ON `${TABLE_NAME}` (`subscriptionId`)"
+          },
+          {
+            "name": "index_episodes_subscriptionId_guid",
+            "unique": true,
+            "columnNames": [
+              "subscriptionId",
+              "guid"
+            ],
+            "orders": [],
+            "createSql": "CREATE UNIQUE INDEX IF NOT EXISTS `index_episodes_subscriptionId_guid` ON `${TABLE_NAME}` (`subscriptionId`, `guid`)"
+          },
+          {
+            "name": "index_episodes_publishedAtMs",
+            "unique": false,
+            "columnNames": [
+              "publishedAtMs"
+            ],
+            "orders": [],
+            "createSql": "CREATE INDEX IF NOT EXISTS `index_episodes_publishedAtMs` ON `${TABLE_NAME}` (`publishedAtMs`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "subscriptions",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "subscriptionId"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      },
+      {
+        "tableName": "queue",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`episodeId` TEXT NOT NULL, `position` INTEGER NOT NULL, PRIMARY KEY(`episodeId`), FOREIGN KEY(`episodeId`) REFERENCES `episodes`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "episodeId",
+            "columnName": "episodeId",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "position",
+            "columnName": "position",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "episodeId"
+          ]
+        },
+        "indices": [
+          {
+            "name": "index_queue_position",
+            "unique": false,
+            "columnNames": [
+              "position"
+            ],
+            "orders": [],
+            "createSql": "CREATE INDEX IF NOT EXISTS `index_queue_position` ON `${TABLE_NAME}` (`position`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "episodes",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "episodeId"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      },
+      {
+        "tableName": "rules",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` TEXT NOT NULL, `name` TEXT NOT NULL, `position` INTEGER NOT NULL, `enabled` INTEGER NOT NULL, `subscriptionId` TEXT, `titleContains` TEXT, `titleExcludes` TEXT, `minDurationMs` INTEGER, `maxDurationMs` INTEGER, `maxAgeMs` INTEGER, `seasonNumber` INTEGER, `action` TEXT NOT NULL, `autoDownload` INTEGER NOT NULL, `speed` REAL, PRIMARY KEY(`id`))",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "position",
+            "columnName": "position",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "enabled",
+            "columnName": "enabled",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "subscriptionId",
+            "columnName": "subscriptionId",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "titleContains",
+            "columnName": "titleContains",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "titleExcludes",
+            "columnName": "titleExcludes",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "minDurationMs",
+            "columnName": "minDurationMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "maxDurationMs",
+            "columnName": "maxDurationMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "maxAgeMs",
+            "columnName": "maxAgeMs",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "seasonNumber",
+            "columnName": "seasonNumber",
+            "affinity": "INTEGER"
+          },
+          {
+            "fieldPath": "action",
+            "columnName": "action",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "autoDownload",
+            "columnName": "autoDownload",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "speed",
+            "columnName": "speed",
+            "affinity": "REAL"
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "id"
+          ]
+        },
+        "indices": [
+          {
+            "name": "index_rules_position",
+            "unique": false,
+            "columnNames": [
+              "position"
+            ],
+            "orders": [],
+            "createSql": "CREATE INDEX IF NOT EXISTS `index_rules_position` ON `${TABLE_NAME}` (`position`)"
+          }
+        ]
+      },
+      {
+        "tableName": "show_fingerprints",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`subscriptionId` TEXT NOT NULL, `kind` TEXT NOT NULL, `referenceClipPcm` BLOB, `pendingClipPcm` BLOB, `pendingEpisodeId` TEXT, `sampleRate` INTEGER NOT NULL, `confirmedCount` INTEGER NOT NULL, `lastConfirmedEpisodeId` TEXT, `updatedAtMs` INTEGER NOT NULL, PRIMARY KEY(`subscriptionId`, `kind`), FOREIGN KEY(`subscriptionId`) REFERENCES `subscriptions`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )",
+        "fields": [
+          {
+            "fieldPath": "subscriptionId",
+            "columnName": "subscriptionId",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "kind",
+            "columnName": "kind",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "referenceClipPcm",
+            "columnName": "referenceClipPcm",
+            "affinity": "BLOB"
+          },
+          {
+            "fieldPath": "pendingClipPcm",
+            "columnName": "pendingClipPcm",
+            "affinity": "BLOB"
+          },
+          {
+            "fieldPath": "pendingEpisodeId",
+            "columnName": "pendingEpisodeId",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "sampleRate",
+            "columnName": "sampleRate",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "confirmedCount",
+            "columnName": "confirmedCount",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "lastConfirmedEpisodeId",
+            "columnName": "lastConfirmedEpisodeId",
+            "affinity": "TEXT"
+          },
+          {
+            "fieldPath": "updatedAtMs",
+            "columnName": "updatedAtMs",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "subscriptionId",
+            "kind"
+          ]
+        },
+        "indices": [
+          {
+            "name": "index_show_fingerprints_subscriptionId",
+            "unique": false,
+            "columnNames": [
+              "subscriptionId"
+            ],
+            "orders": [],
+            "createSql": "CREATE INDEX IF NOT EXISTS `index_show_fingerprints_subscriptionId` ON `${TABLE_NAME}` (`subscriptionId`)"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "table": "subscriptions",
+            "onDelete": "CASCADE",
+            "onUpdate": "NO ACTION",
+            "columns": [
+              "subscriptionId"
+            ],
+            "referencedColumns": [
+              "id"
+            ]
+          }
+        ]
+      }
+    ],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, '564d893d23f7e7f14cb4afc1b65c83f0')"
+    ]
+  }
+}
\ No newline at end of file