feat(console-web): complete create member flows

[potter-sun]

Summary

• routes Workflow, Script, and GAgent create-member choices through backend member authority creation
• removes Script/GAgent transitional handoff copy and opens the matching Build surface after creation
• adds GAgent naming and coverage for backend-created GAgent members

Closes #653

Verification

• npm --prefix apps/aevatar-console-web run test -- --runInBand src/pages/studio/index.test.tsx src/pages/studio/components/StudioShell.test.tsx
• npm --prefix apps/aevatar-console-web run tsc
• npm --prefix apps/aevatar-console-web run build
• git diff --check

Notes: Jest still prints existing React act(...) warnings and Watchman recrawl warnings; all targeted tests passed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.12%. Comparing base (195bb0b) to head (d5e42d8).

@@            Coverage Diff             @@
##              dev     #659      +/-   ##
==========================================
- Coverage   72.13%   72.12%   -0.01%     
==========================================
  Files        1261     1261              
  Lines       91065    91065              
  Branches    11924    11924              
==========================================
- Hits        65691    65684       -7     
- Misses      20675    20681       +6     
- Partials     4699     4700       +1     

Flag	Coverage Δ
ci	72.12% <ø> (-0.01%)	⬇️

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see 2 files with indirect coverage changes

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