android: the handoff — the pending rounds, the pipeline, and what is unverified

Everything written this session that has not been through the device: rounds 43
to 48 (each patch adversarially verified, 43's transient-notice expectation
fixed), a partial round 49, the pipeline scripts, the Android Auto design and
the icon comparison mock. Also the two harness changes that were never A/B'd —
adaptive waits, which may only shorten a declared wait and never lengthen it,
and a ship that runs the mock walk and the deploy at the same time. The A/B and
its 255-step baseline are in handoff/tools; main stays at what the phone has
actually walked.

handoff/rounds/commit-msg36.txt

@@ -0,0 +1,32 @@
+android: a playlist file, picked
+
+The storage plugin grew `pick_file` beside `pick_folder` and `pick_image`:
+the document sheet with the caller's own filter, answered with a path Rust
+can open. A document already on this phone hands its path over as it lies —
+the document sibling of the same volume:relative id the folder picker
+resolves, plus the Downloads provider's raw: — so a 300 MB pick copies
+nothing; one that has no path is copied into cacheDir/picked under its own
+name, and only as far as the caller allows, because a playlist is kilobytes
+and a DJ set is not. Those copies are swept at the start of every pick,
+which pick_image's never were.
+
+The import sheet has its fifth door, on round 24's screen, wait card and
+review, and the note that apologised for its absence says the one true thing
+about it instead. `playlist_import_probe` took a path and a name the way
+`playlist_import_folder` took a path, and the name is the load-bearing half:
+the parser picks its format off the extension and titles the draft from the
+stem, so a cache copy under an invented name would have read every playlist
+as plain text. The mock walk drives the door and both of the picker's
+refusals through round 31's fail door; the phone walk opens the real sheet
+and dismisses it with BACK, reading nothing and writing nothing.
+
+The brief asked for a second consumer — sending a file in a chat — and there
+is nothing behind it: `community_pick_file` is the persona layer's three
+native dialogs, `soulseek-client` has `say_room` and `message_user` and
+nothing that sends a file, and both frontends' thread composers are text
+only. Nothing was invented for it. The plugin command is general enough — a
+caller's own filter, a zero-copy path, a bounded copy — that the one reader
+still waiting, the local set listener the phone puts off by design, needs no
+further plugin change. Playlist export is not on that list and never was:
+writing a document out is the share plugin's errand, not a picker's. The
+Kotlin is unbuilt — nothing on this machine compiles it.