Sync PRODUCT docs with Alt+A models-only connect

[TheGreatAxios]

Summary

Align product and implementation docs plus operator-facing auth messages with the connect stack that just landed (CL-5898/5899/5900):

• /model is models-only (connected accounts); Alt+A is the add-provider path
• Remove stale bare-c / Ctrl+A / in-list “connect →” instructions
• Document named OAuth accounts and named API-key multi-instance behavior as shipped
• Point auth-failure guidance at Alt+A

Linear: CL-5901

Verification

• bun run typecheck
• bun run build
• bun run test (4547 pass)

[linear-code]

CL-5901

[TheGreatAxios]

Reviewer-of-record

Lens: branch vs origin/main, commit style, full diff
Verdict: approve
Summary: Docs and operator-facing auth strings match the shipped models-only /model + Alt+A connect stack; no code behavior change beyond message text.

Findings: none

Gate notes: single commit a5739ec, subject plain-English imperative under 72 chars, full gate green in worktree (typecheck/build/test 4547).

[TheGreatAxios]

Critique

Lens: behavioral accuracy and maintainability of user-facing copy
Verdict: approve
Summary: PRODUCT and IMPLEMENTATION now describe models-only list, Alt+A add-provider, named OAuth/API-key instances, and Custom without teaching printable Connect keys under type-to-filter.

Findings: none

[TheGreatAxios]

Greybeard

Lens: architecture/docs consistency after CL-5898/5899/5900
Verdict: approve
Summary: Documentation and auth-failure guidance track the multi-instance connect contract that already landed on main; no speculative prose.

Findings: none

[TheGreatAxios]

gaasbot

Lens: public OSS release readiness
Verdict: approve
Summary: Operator docs and error strings are suitable for public users; no secrets, machine paths, or internal-only assumptions introduced.

Findings: none

[TheGreatAxios]

Reviewer-of-record

Lens: branch vs origin/main, commit style, full diff
Verdict: clean
Summary: Docs and operator-facing auth strings match the shipped models-only /model + Alt+A connect stack; no code behavior change beyond message text.

Findings: none

Critique

Lens: behavioral accuracy of user-facing copy
Verdict: clean
Summary: PRODUCT and IMPLEMENTATION describe models-only list, Alt+A add-provider, named OAuth/API-key instances, and Custom without teaching printable Connect keys under type-to-filter.

Findings: none

Greybeard

Lens: architecture/docs consistency after CL-5898/5899/5900
Verdict: clean
Summary: Documentation and auth-failure guidance track the multi-instance connect contract on main.

Findings: none

gaasbot

Lens: public OSS release readiness
Verdict: clean
Summary: Operator docs and error strings are suitable for public users; no secrets or internal artifacts.

Findings: none