one unknown platform name in the Skillfile breaks `install --update`, `info`, and `status` - while plain `install` correctly skips it

[eljulians]

Component: crates/deploy (paths.rs, install.rs) | Severity: High (forward-compat promise broken) | Status: Reproduced

The project's own test suite documents that unknown adapters must be skipped gracefully ("lets new platform names be added to a Skillfile without breaking existing installs") and plain install does warn-and-skip. But the shared path helpers propagate adapter_for(target)? errors, so with install shiny-new-tool local present alongside install claude-code local:

• skillfile install --update exits 1 with "unknown adapter 'shiny-new-tool'" before syncing anything (via the auto-pin pass).
• skillfile info <name> exits 1 with the same error.
• skillfile status shows installed entries as [not installed] (per-target errors collapse the installed-path set) and silently disables drift detection.

A teammate on a newer skillfile version adding a new platform to the shared manifest thus breaks older clients' core commands.

Where: crates/deploy/src/paths.rs:45 and :80 (let adapter = adapter_for(target)?; inside per-target loops), paths.rs:142-148; crates/deploy/src/install.rs:171-175, :189 (auto-pin path).

Repro:

printf 'install  claude-code  local\ninstall  shiny-new-tool  local\nlocal  skill  s  skills/s.md\n' > Skillfile
mkdir skills && printf x > skills/s.md
skillfile install            # warns + succeeds (correct)
skillfile status             # s ... [not installed]  ← false
skillfile info s             # error: unknown adapter 'shiny-new-tool', exit 1
skillfile install --update   # exit 1 before doing anything

Expected: all commands skip unknown adapters exactly like deploy_all does (warn once).
Actual: hard failure of --update/info, false [not installed] in status.

Fix sketch: in installed_paths/installed_dir_file_sets/auto-pin loops, replace adapter_for(target)? with a match that warns and continues on unknown adapters.

Tests:

1. Unit (crates/deploy/src/paths.rs): manifest with one known + one unknown target → installed_paths returns the known target's path, no Err.
2. Integration (crates/deploy/tests/install_deploy_all.rs): the existing unknown-adapter fixture, extended to update: true → assert success.
3. Functional (tests/cli.rs): the repro above; status shows no [not installed], info exits 0.