feat(agent): discover Databricks Unity Catalog models

.env.example

@@ -172,6 +172,12 @@ RUST_LOG=buzz_relay=debug,buzz_datastore=info,buzz_db=debug,buzz_auth=debug,buzz
 # Use `buzz-acp models` to discover available model IDs.
 # BUZZ_ACP_MODEL=
 
+# Optional Databricks model-picker visibility filter. Discovery-only; this does
+# not grant inference access. Comma-separated full-string * / ? patterns are
+# OR-matched against raw workspace endpoint and Unity Catalog model-service IDs.
+# Unset or blank shows every catalog entry. A nonblank value with no usable patterns is invalid.
+# DATABRICKS_MODEL_FILTER=databricks-*,data_tools.goose.*
+
 # ── Timeouts & sessions ──────────────────────────────────────────────────────
 # Max seconds per agent turn before timeout (default 320 = ~5 min).
 # BUZZ_ACP_TURN_TIMEOUT=320

crates/buzz-agent/README.md

@@ -149,6 +149,7 @@ Everything is environment variables. No flags, no config files. (We are a subpro
 | `OPENROUTER_BASE_URL` | `https://openrouter.ai/api/v1` | |
 | `DATABRICKS_HOST` | — | Required when provider=databricks or provider=databricks_v2. |
 | `DATABRICKS_MODEL` | — | Required when provider=databricks or provider=databricks_v2. |
+| `DATABRICKS_MODEL_FILTER` | — | Optional discovery-only, comma-separated full-string `*`/`?` patterns OR-matched against raw Databricks endpoint and Unity Catalog model-service IDs. Blank/unset shows all; this is visibility filtering, not an authorization boundary. |
 | `DATABRICKS_TOKEN` | — | Optional static bearer escape hatch. If unset, Databricks uses browser OAuth + refresh cache. |
 | `BUZZ_AGENT_SYSTEM_PROMPT` | built-in | Inline system prompt. |
 | `BUZZ_AGENT_SYSTEM_PROMPT_FILE` | — | File path. Mutually exclusive with the above. |
@@ -241,7 +242,9 @@ lifecycle hook — see [MCP_DRIVEN_HOOKS.md](../../docs/MCP_DRIVEN_HOOKS.md).
 | Block Gateway | `openai` | `POST {base}/chat/completions` | gpt-5, claude |
 | OpenRouter | `openrouter` | `POST {base}/chat/completions` | anything they route (extended-thinking replay, provider-agnostic tool calling) |
 | Databricks | `databricks` | `POST {host}/serving-endpoints/{model}/invocations` | goose-claude-4-6-sonnet |
-| Databricks AI Gateway v2 | `databricks_v2` | `POST {host}/ai-gateway/{provider}/v1/...` | databricks-gpt-5-5, databricks-claude-opus-4-7 |
+| Databricks AI Gateway v2 | `databricks_v2` | `POST {host}/ai-gateway/{provider}/v1/...` | workspace endpoints and Unity Catalog model-service FQNs; UC FQNs use MLflow Chat Completions |
+
+The optional `DATABRICKS_MODEL_FILTER` applies only to model discovery. Each comma-separated entry is trimmed and matched against the complete raw ID with case-sensitive `*` (zero or more characters) and `?` (one Unicode character) semantics; patterns are OR-ed. Unset or blank preserves the full authenticated catalog. A nonblank value containing no usable patterns is rejected. This controls picker visibility only; Databricks and Unity Catalog permissions remain the authorization boundary. A filtered-empty result is authoritative and does not restore the built-in fallback models.
 
 If `BUZZ_AGENT_PROVIDER=anthropic` is selected without `ANTHROPIC_API_KEY`, `BUZZ_AGENT_PROVIDER=openai` is selected without `OPENAI_COMPAT_API_KEY`, or `BUZZ_AGENT_PROVIDER=openrouter` is selected without `OPENROUTER_API_KEY`, the agent returns an error — there is no implicit fallback to another provider.