feat: feedback capture — issue templates, pinned discussion, no telemetry

[gkanitz]

Context

Launch-readiness item. The public push needs a place for feedback to land,
structured enough to be usable and honest about the project's privacy
stance: no telemetry, ever — feedback is explicit or it doesn't exist.

Goal

GitHub-native feedback capture: issue templates + a pinned discussion +
visible entry points, so launch feedback arrives sorted by audience instead
of as drive-by comments.

In scope

• .github/ISSUE_TEMPLATE/bug_report.yml — platform, run mode
  (local / org CI / personal CI), what happened vs expected; reminder not
  to paste report contents containing private repo names they don't want
  public.
• .github/ISSUE_TEMPLATE/feedback.yml — structured by audience: I'm a
  developer who ran it / a recruiter-EM who received one / an org admin
  who was asked to approve one. Asks: what convinced you, what confused
  you, what's missing before you'd use it for real.
• .github/ISSUE_TEMPLATE/config.yml — blank issues off, contact link to
  the pinned discussion.
• README + docs/index.html: a short "Feedback" section linking the
  templates and discussion.
• Owner steps documented as checkboxes in this issue: enable GitHub
  Discussions, create + pin a "Launch feedback" discussion.

Out of scope

• Any telemetry, analytics, or tracking in the CLI, report, or pages.
  External form services. Report-template changes.

Acceptance criteria

Success

1. Template YAML is valid — the new-issue chooser renders all templates
   (verifiable via GitHub's template rendering after merge; YAML lint in
   tests where the repo has one).
2. The feedback template branches by the three audiences and each branch
   asks the three questions above.
3. Blank issues disabled; config contact-link points at the discussion.
4. README and landing page carry the feedback links.
5. git grep-verifiable absence of any analytics/telemetry addition —
   the diff touches only templates and docs.
6. Owner checkboxes for Discussions + pinning are present in this issue and
   ticked before it closes.

Failure — QA red flags

• Any tracking pixel, analytics script, or phone-home addition anywhere.
• Templates that ask reporters to paste full report files without the
  privacy reminder.
• Free-form blank issues left enabled.

Parallel-work contract

• Territory: .github/ISSUE_TEMPLATE/ (new), README + docs/index.html
  (additive sections).
• Depends on: nothing — start immediately.