feat(profiles): prune the gstack catalog, add max, honor a removed denylist

Nine gstack skills leave every profile (ship is trunk-based on Gitea,
land-and-deploy auto-merges and deploys, setup-deploy, autoplan reads
paths that do not exist here, context-save has no restore, learn is an
unused parallel store, careful and guard hooks never fired, design-shotgun
needs an absent OpenAI key). lib/gstack-removed.sh is the single denylist;
profile.sh gstack on and toggle-external.sh enable gstack skip it.

full now carries everything every other profile carries (user rule), minus
the parked make-pdf, diagram and 21st-ai/ui-explore/ui-review, which live
in the new max profile together with pr-review-toolkit. The 21st trio also
leaves web, web-full and design (redundant with impeccable + ui-ux-pro-max).

lib/tests/profile-census.test.sh asserts the invariants live and on a
baseline fixture plus one mutant per invariant; gstack-removed.test.sh
covers both restore paths.

lib/profiles/web.profile

@@ -4,7 +4,6 @@
 # For SEO/GEO audit on top, use web-full or apply seo afterwards.
 
 # Design skills (gstack) — full design pipeline
-design-shotgun
 design-review
 design-consultation
 design-html
@@ -23,9 +22,7 @@ plan-eng-review
 feat                              personal
 ship-feature                      personal
 hotfix                            personal
-ship                                                # gstack
 review                                              # gstack
-context-save                                        # gstack
 commit-change                     personal
 refactor                          personal
 
@@ -51,10 +48,7 @@ site-motion                       personal
 # External: 21st.dev pack (publishing flows 21st-registry / -design-sync
 # stay parked)
 21st-ui-build                     external
-21st-ui-explore                   external
-21st-ui-review                    external
 21st-cli-use                      external
-21st-ai                           external
 
 # Plugin: UI/UX intelligence (auto-toggle)
 ui-ux-pro-max                     plugin@ui-ux-pro-max-skill