`_tui_need_npm_install()` compares the canonical `package-lock.json` against
the hidden `node_modules/.package-lock.json` to decide whether `npm install`
needs to re-run. npm 9 drops the `"peer": true` field from the hidden lock
on dev-deps that are *also* declared as peers (the canonical lock preserves
the dual annotation). That made the check flag 16 packages (`@babel/core`,
`@types/node`, `@types/react`, `@typescript-eslint/*`, `react`, `vite`,
`tsx`, `typescript`, …) as mismatched on every launch, triggering a runtime
`npm install`.
Inside the Docker image, that runtime install then fails with EACCES because
`/opt/hermes/ui-tui/node_modules/` is root-owned from build time, so
`docker run … hermes-agent --tui` prints:
    Installing TUI dependencies…
    npm install failed.
…and exits 1, with no preview. The empty preview is a second bug: the
launcher captured only stderr, but npm 9 writes EACCES to stdout, which
was DEVNULL'd.
Fixes:
 - Add `"peer"` to `_NPM_LOCK_RUNTIME_KEYS` so the comparison ignores the
   non-deterministic field, alongside the existing `"ideallyInert"`.
 - Capture stdout as well as stderr in the install subprocess so future
   failures surface a useful preview instead of a bare "failed." line.
Regression tests:
 - `test_no_install_when_only_peer_annotation_differs` — the exact scenario
 - `test_install_when_version_differs_even_with_peer_drop` — guards against
   the peer-drop tolerance masking a real version skew
On-host impact: the same false-positive was firing on every `hermes --tui`
invocation from a normal checkout, silently running a no-op `npm install`
each time (it converged because the host's `node_modules/` is writable).
Startup time on the TUI should drop noticeably.