Three coordinated tweaks to the publication discovery surface:
1. Action-row CTA on /marketplace?tab=curated reads 'Submit a skill
or plugin' instead of 'Submit a plugin'. Skills are first-class
citizens of the curated shelf; the old wording made them feel
like an afterthought. Same rename in the empty-state JS innerHTML
so the two paths can't drift.
2. Curated guide page (/marketplace/guide/curated) expanded from a
4-line stub into a 3-step ordered list documenting the Named
Curator handoff (find curator → handoff → publish + lifecycle).
New '.guide-fastpath' callout block points users at the Flea
Market when they want lighter review-bar / faster path. Primary
CTA at the bottom of the curated guide now links to the flea
guide too, so users who skim past the fast-path callout still
see the escape hatch.
3. Flea guide page (/marketplace/guide/flea) expanded from a
3-line stub into a 4-step ordered list (package → upload via
form → automated review → published). Documents the actual
/store/new flow + the automated guardrails (manifest, content
quality, prompt-injection scan) so users know what 'self-service'
actually means before they upload.
Route titles updated to match: 'Submit a skill or plugin to
Curated Marketplace'.
New file: tests/test_web_marketplace_guide.py — three tests covering
the CTA rename, the curated guide's structural elements (Named
Curators lede, 3 steps, fastpath callout, primary-CTA href), and
the flea guide's structural elements (4 steps, no fastpath
asymmetry, /store/new primary CTA).
