ADR-0063 follow-up: collapse data-chat naming drift + skill→shell affinity + tier-aware routing

[xuyushun441-sys]

Follow-up to ADR-0063 (#2164) — the mechanical landing of the two-shell (ask/build) + skills-only model. The ask id is already canonical, but code/files still speak 'data-chat', which is the physical source of the id≠name ambiguity.

Naming cleanup (kills the id≠name drift)

• Rename packages/services/service-ai/src/agents/data-chat-agent.ts → ask-agent.ts; update agents/index.ts re-exports.
• DEFAULT_DATA_AGENT_NAME → ASK_AGENT_NAME (retain LEGACY_DATA_AGENT_NAME = 'data_chat' as the alias constant).
• Sweep docs/prose: 'data agent' / 'Data Assistant' → 'ask agent' / the ask id. Keep data_chat / metadata_assistant only in the alias table, never as vocabulary.

Skill → shell affinity (the one new contract)

• Add surface: 'ask' | 'build' | 'both' to the skill schema in @objectstack/spec.
• Backfill built-ins: data_explorer/actions_executor → ask; metadata_authoring/solution_design → build.
• Routing loads only a shell's affine skills (build shell shouldn't drown in data skills, and vice versa).

Tier-aware routing

• Per-turn intent routing must not assume both shells exist: on OSS/free (only ask present) a build-intent turn degrades gracefully ('authoring needs the cloud Build assistant') instead of dead-ending.
• Document at the skill-authoring contract that surface:'build' skills are inert on OSS (intentional tiering, not a bug).

Withdraw the tenant-agent surface (ADR-0040 §3)

• Remove any app.defaultAgent → tenant-authored-agent assumptions in ../objectui / Studio.
• Close *.agent.ts as a third-party authoring surface (keep it internal to platform-owned shells/subagents).

All independently shippable; none changes a public id. See docs/adr/0063-two-kernel-agents-skills-are-the-extension-primitive.md.

[xuyushun441-sys]

Closing as superseded by #2168 (the ADR-0063/0064 implementation tracker). Every item here landed there or in the doc PR below — keeping two ~90%-overlapping issues open was causing double-tracking.

Where each item landed:

Naming cleanup

• ✅ data-chat-agent.ts → ask-agent.ts; DEFAULT_DATA_AGENT_NAME → ASK_AGENT_NAME; LEGACY_DATA_AGENT_NAME='data_chat' retained — feat(ai): split ask/build agents by surface + tool scoping (ADR-0063/0064) #2181.
• ✅ Prose sweep ('data agent'/'Data Assistant' → ask; data_chat/metadata_assistant alias-table only) — the remaining gap (skills/objectstack-ai/SKILL.md still on the old ADR-0040 unified model) is fixed in docs(skills): sweep objectstack-ai SKILL.md to the ask/build two-agent model (ADR-0063/0064) #2194.

Skill → shell affinity

• ✅ surface: 'ask' | 'build' | 'both' on SkillSchema + backfill — feat(ai): split ask/build agents by surface + tool scoping (ADR-0063/0064) #2181 (OSS: schema_reader=both, data_explorer/actions_executor=ask) and cloud#417 (metadata_authoring/solution_design=build).
• ✅ Routing loads only affine skills — resolveActiveSkills enforces it as a fast load error — feat(ai): split ask/build agents by surface + tool scoping (ADR-0063/0064) #2181.

Tier-aware routing

• ✅ Build-intent degrades gracefully on OSS — ask declines+redirects (no per-turn classifier); objectui graceful handling ([P2] create_record outputVariable may not be referenceable in later flow nodes (needs confirm) #1873).
• ✅ Documented that surface:'build' is inert on OSS (intentional tiering) — docs(skills): sweep objectstack-ai SKILL.md to the ask/build two-agent model (ADR-0063/0064) #2194.

Withdraw tenant-agent surface

• ✅ agent type allowRuntimeCreate:false, allowOrgOverride:false + catalog filtered to platform agents — feat(ai): split ask/build agents by surface + tool scoping (ADR-0063/0064) #2181.
• ✅ Dropped app.defaultAgent custom-agent guidance — cloud#417; objectui surface binding already in place.

D4 (deployment guardrail-floor) stays deferred per the audit. Tracking continues in #2168.