docs(specs): record what shipped, and where the design bent

DR-242 … DR-247 are in. The spec now says so rather than reading as a proposal
for work that already exists.

One deviation is recorded rather than quietly absorbed: DR-246 called for the
engines to own seek strategy outright, and they cannot — re-negotiating a
stream needs the repository, which sits above them. The engine declares the
ability and the caller acts on it. `determine_video_seek_strategy` therefore
survives, correctly typed over a declared capability instead of over a guess,
because the defect was its input rather than its existence.

docs/specs/media-player-controller.md

@@ -1,6 +1,11 @@
 # Spec: MediaPlayer — one controller API, three interchangeable engines
 
-**Status:** Proposed
+**Status:** **Partially implemented.** DR-242 … DR-247 have shipped: the
+contract, `FakePlayer` and the conformance suite, `MpvPlayer`, the standalone
+runner, `LegacyPlayer`, the controller port, the capability-driven seek
+strategy, and ExoPlayer conformance on a device. What is left is DR-248 (the
+webview as an engine) and DR-249 (deleting `PlayerBackend` and the frontend
+playback-state flags).
 **Requirements:** UR-081 (new) → DR-242 … DR-249 (new); IR-034. Re-check
 `requirements.md` before allocating — ids moved several times while this was
 written.
@@ -226,6 +231,15 @@ Strangler, not a rewrite. Each step ships independently and leaves the app worki
    behind an adapter so the other engines keep working.
 5. **DR-246** Move seek strategy and reload orchestration out of
    `commands/player/mod.rs` into the engines; delete `seek.rs`'s truth table.
+
+   **Shipped with a deviation.** The engine cannot own this outright:
+   re-negotiating a stream needs the repository, which sits *above* the engine.
+   So the engine *declares* `seeks_transcoded_in_place` and the caller acts on
+   it. That removes the defect — nobody guesses on another component's behalf,
+   and adding an engine no longer means editing a shared table — without
+   pretending an engine can reach upward. `determine_video_seek_strategy`
+   survives as a correctly-typed decision over declared abilities rather than
+   being deleted; the defect was its *input*, not its existence.
 6. **DR-247** `ExoPlayerPlayer`; conformance on device.
 7. **DR-248** `WebviewPlayer`; retire the adapter shim.
 8. **DR-249** Delete `PlayerBackend` and the frontend playback-state flags.