fix(cli): persist authoring skill in hyperframes.json for durable render attribution (#2762)

* fix(cli): persist authoring skill in hyperframes.json for durable render attribution

authoring_skill was stamped only on the first render through a workflow
passing --skill, so re-renders, `npm run render`, --batch, existing-project
renders, and general-video lost it — leaving 77-96% of real-human render
volume un-attributed and the skills-penetration metric misleadingly low.

Persist the owning skill in hyperframes.json: `init --skill` stamps it at
creation, `render` resolves the flag then falls back to the stored value, and
an explicit --skill seeds it (seed-once, never overwriting the creating
workflow's identity). Activate all render-producing creation workflows to
declare their skill at init.

Forward-only: does not rewrite historical telemetry.

* fix(cli): patch hyperframes.json in place when seeding the authoring skill

seedProjectAuthoringSkill is the only writer that touches an already existing
hyperframes.json — every other writeProjectConfig call site is guarded to write
only when the file is absent, which made the whole-file overwrite safe by
construction. Round-tripping the seed through normalizeConfig broke that: it
rebuilds the object from a field whitelist with no rest-spread, so any key
outside the schema was silently dropped, a media block was materialized in
projects that never had one, and key order was rewritten. hyperframes.json is
normally committed, so a render introduced a diff the user never asked for, and
any field added to the schema later would be deleted by a render on an older
CLI.

Parse the raw JSON, set authoringSkill, write it back, reusing the file's own
indentation. Unknown keys and formatting survive; the only delta is the key
being added. A corrupt config is now left untouched instead of clobbered.

Seed-once semantics are unchanged, still normalized so a hand-edited garbage
slug neither reaches telemetry nor wedges the seed.

Reported independently by both reviewers on #2762.

* fix(cli): create the docker build context with mkdtempSync

The `--docker` build context was created at a guessable path derived from
`Date.now()` in the world-writable OS temp dir. Another local user can
pre-create or symlink that path and have the build read a Dockerfile they
control. mkdtempSync gets a random suffix and 0o700 from the kernel, and it
creates the directory itself, so the separate mkdirSync goes away.

Pre-existing on main (alert #432, 2026-06-04, packages/cli/src/commands/render.ts),
surfaced against this branch only because the seed commit shifted line numbers in
the same file. Fixed here to unblock the CodeQL gate on #2762 rather than left for
a follow-up; the remaining 10 js/insecure-temporary-file alerts elsewhere in the
repo are untouched and still want their own pass.

* fix(cli): drop the check-then-use race when seeding the authoring skill

The seed tested for the config with existsSync and then wrote, which is a
check-then-use race: the file can be created or swapped between the check and
the write (CodeQL js/file-system-race).

Read once and branch on the failure reason instead. Only ENOENT creates a
config from scratch; any other read failure (permissions, I/O) now leaves an
existing file alone rather than overwriting it with a default, so this is also
strictly safer than the version it replaces.

Also replaces the `as Record<string, unknown>` assertion with an isJsonObject
type guard, per the repo's no-assertion convention.

Behaviour unchanged: all 4 seed regression tests still pass, and the
create/preserve/seed-once/corrupt-untouched paths were re-verified end to end.

skills/general-video/SKILL.md

@@ -39,7 +39,7 @@ Apply the first matching row; do not evaluate lower state rows:
 For a new project, choose a kebab-case directory name from the brief and scaffold before writing the brief:
 
 ```bash
-npx hyperframes init "videos/<project>" --non-interactive --example=blank
+npx hyperframes init "videos/<project>" --non-interactive --example=blank --skill=general-video
 ```
 
 Then write `BRIEF.md` at the project root using `../hyperframes-core/references/brief-format.md`. In an existing project, the root is the directory containing `hyperframes.json`. Record only the confirmed preference-backed fields named by the brief format, using `node <MEDIA_DIR>/scripts/prefs.mjs record --hyperframes <PROJECT_ROOT>`; never record inferred defaults. Here `<MEDIA_DIR>` is the installed `/media-use` skill directory and `<PROJECT_ROOT>` is the directory containing `hyperframes.json`. If the intent layer adopted a recipe, apply it now with `node <MEDIA_DIR>/scripts/recipe.mjs use --hyperframes <PROJECT_ROOT> --name <name>` and do not ask again.