feat: install release builds and report missing FFmpeg

Add make release and make install PREFIX=/Users/valdemar/.local. Keep optimized no-debug release artifacts separate; install adjacent CLI/app under lib/terebi and link bin/terebi. Preflight FFmpeg/pkg-config before compiling or installing, including cached builds.

Record the player's exact linked FFmpeg ABI paths. AppKit-only CLI/bootstrap validate native loadability and transitive dependencies before entering the FFmpeg-linked terebi-player. CLI fails with status 69 and remediation; Finder bootstrap shows a native alert and execs the player without losing initial events or process identity.

Verified staged installation with spaces, reinstall preservation, absent build dependencies, missing/corrupt/transitively broken dylibs, real modal error surface, installed CLI and Finder startup across exec, local/YouTube resume and window reuse, and full make check.

README.md

@@ -12,10 +12,26 @@ make
 make run
 ```
 
-The local app is `.build/terebi.app`. It links the installed FFmpeg libraries; it is not a standalone distributable bundle. After upgrading FFmpeg, rebuild with `make -B`.
+The developer app is `.build/terebi.app`. It links the installed FFmpeg libraries; it is not a standalone distributable bundle. After upgrading FFmpeg, rebuild with `make -B` or reinstall with `make -B install`.
 
 Open a local file with **⌘O**, drop it onto the window, or use Finder's **Open With**. Successfully opened files start playback automatically, including when replacing the current file. **⇧⌘W** closes the file; closing the window quits and joins the worker.
 
+## Release and installation
+
+```sh
+make release                         # optimized build in .build/release, without -g
+make install                         # default PREFIX=$HOME/.local
+make install PREFIX="/custom/path"   # optional installation prefix
+export PATH="$HOME/.local/bin:$PATH"
+terebi --help
+```
+
+Installation puts the CLI at `~/.local/lib/terebi/terebi` and the app beside it at `~/.local/lib/terebi/terebi.app`; `~/.local/bin/terebi` is a symlink to the CLI. A custom `PREFIX` uses the same `lib/terebi` and `bin` layout. The default needs no sudo. Release artifacts are separate from developer builds, and reinstall replaces the installed app bundle without touching unrelated prefix contents. Close a running player and relaunch after installing an update.
+
+FFmpeg is still external. Builds and installs—including cached release installs—check `pkg-config` and all five FFmpeg development packages before compiling or copying. Missing dependencies report `brew install ffmpeg pkg-config`.
+
+At runtime, both the CLI and the app's lightweight bootstrap check the exact FFmpeg dylibs linked by the player, including their transitive dependencies. Missing, incompatible, or broken libraries report `brew install ffmpeg` and explain that library-version changes require rebuilding/reinstalling terebi. The CLI exits **69**; Finder launches show a native error dialog instead of failing in dyld before the UI starts. Missing or invalid dependency metadata also reports rebuild/reinstall. CLI help remains available without FFmpeg.
+
 ## Command line
 
 `make` also builds `.build/terebi`, a native CLI launcher:
@@ -32,7 +48,7 @@ One local file (including a local `file://` URL) or YouTube video URL is accepte
 
 The launcher finds `terebi.app` beside its own executable, following symlinks, and uses macOS application/URL delivery to reuse the running player and its existing window. Keep the executable and app bundle together; this is not a standalone distribution. Media opens use the same autoplay and saved-progress behavior as the UI. Relaunch an older running build once to load the new external-open handling.
 
-Help exits with status **0** without opening the GUI. Invalid arguments, unsupported URLs, missing files, and directories report to stderr and exit **64**; application-launch failures exit **69**. A successful launch exits **0** immediately after macOS accepts the request, not when playback finishes. Later extraction/decoding failures appear in the player window; this is a GUI launcher, not a headless player or remote playback-control interface.
+Help exits with status **0** without opening the GUI or loading FFmpeg. Invalid arguments, unsupported URLs, missing files, and directories report to stderr and exit **64**; unavailable FFmpeg libraries and application-launch failures exit **69**. A successful launch exits **0** immediately after macOS accepts the request, not when playback finishes. Later extraction/decoding failures appear in the player window; this is a GUI launcher, not a headless player or remote playback-control interface.
 
 ## YouTube
 
@@ -99,7 +115,8 @@ Only implemented actions have controls; there are no placeholder playlist, subti
 - `Sources/App/CompactWindow.swift`: same-window compact geometry, saved normal window state, asynchronous fullscreen transitions and failure recovery, all-Spaces/floating behavior, magnetic edge snapping, and its persisted preference.
 - `Sources/App/YouTubeResolver.swift`: YouTube URL and metadata validation, external yt-dlp/runtime discovery, SDR stream selection and headers, bounded nonblocking process output, sanitized extraction errors, and request-local cancellation.
 - `Sources/CLI/PlayerCommand.swift` and `Sources/CLI/TerebiCLI.swift`: command-line validation/help and native application discovery/launching. Launch the app without media first to establish its singleton window, then deliver the selected URL; the app owns Apple events to prevent SwiftUI's default external-document routing from replacing that window.
-- `Makefile`: compiler/linker commands and app bundle construction. No generated Xcode project or additional build dependency.
+- `Sources/Launcher/FFmpegRuntime.swift` and `Sources/App/Bootstrap.swift`: shared native dependency preflight and the app's FFmpeg-independent entrypoint. The bootstrap execs `terebi-player` without changing its PID/arguments or consuming initial launch events. `Contents/Resources/ffmpeg-libraries.txt` records the payload's actual linked FFmpeg ABI paths.
+- `Makefile`: compiler/linker commands, dependency preflight, generated runtime manifest, developer/release bundles, installation, and checks. No generated Xcode project or additional build dependency.
 
 ## Runnable check
 
@@ -121,6 +138,8 @@ Generates short fixtures and exercises the real playback interface and native ou
 
 `make check-cli` checks relative/escaped paths, option-like filenames, YouTube identity, argument cardinality, unknown options, missing files/directories, non-local file URLs, and unsupported stream URLs. It is included in `make check`.
 
+`make check-runtime` exercises missing/invalid dependency metadata, unavailable ABI libraries, existing but unloadable dylibs, omitted library families, and successful native library loading using isolated app metadata. It is included in `make check`; no installed FFmpeg files are modified.
+
 Continuous audio uses resampled sample counts for its output timeline; packet timestamp quantization and rounded resampler delay must not insert silence or drop samples between blocks.
 
 Volume persists across open, seek, and close. Live gain changes ramp over five milliseconds without callback allocation or locking; a stopped output adopts the requested gain before playback starts, so muted startup cannot leak audio.