fix(qwen): gadfly round 2 — the anti-drift list had already drifted

Eight findings, all real, and the sharpest ones are about this PR's own fixes.

GADFLY_API_KEY was treated as a universal substitute in the pre-flight. It is
not: resolveModel reads it only AFTER the `baseURL == ""` early return, so on
the registry path — the documented primary path — a qwen/kimi built-in reads
its own variable and GADFLY_API_KEY is never consulted. A mis-set
GADFLY_API_KEY therefore passed pre-flight and 401'd five times anyway, which
is precisely the failure this check exists to prevent. It now only substitutes
when GADFLY_BASE_URL is also set.

`openai-compatible` was missing from the pre-flight table while both switches
accept it as an OPENAI_API_KEY alias, so that one spelling still fell through
to the cryptic five-failure mode.

endpointProviderNames — the constant I introduced *to stop* the two error
messages drifting — omitted the `gemini` alias both switches accept. It now
lists every accepted spelling.

And the case list itself was still duplicated across both switches plus the
test that pins them: three copies of the thing whose duplication started this.
Both switches now call isOpenAICompatProvider over one shared slice, and
endpointProvider's doc comment points at endpointProviderNames instead of
carrying a fourth hand-written copy.

scripts/preflight_test.sh moves into the repo (20 cases, up from 17, covering
openai-compatible and both GADFLY_API_KEY directions). It carries a drift guard
that diffs its copy of the provider table against run.sh's and aborts if they
differ — break-checked by deleting an arm from run.sh, which fails it loudly.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

cmd/gadfly/model.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"slices"
 	"strings"
 
 	"gitea.stevedudenhoeffer.com/steve/majordomo"
@@ -19,12 +20,33 @@ import (
 // model list is just ids like "qwen3-coder:480b-cloud" — working unchanged.
 const defaultProvider = "ollama-cloud"
 
+// openAICompatProviders are the provider names that resolve to the plain
+// openai client at an explicit base URL. openai-compatible is the generic
+// spelling; kimi (Moonshot) and qwen (Alibaba Model Studio) are majordomo
+// built-ins that ARE that client pointed elsewhere, so an explicit endpoint for
+// either belongs on the same branch.
+//
+// This is a slice rather than three copies of a case list because there are
+// three places that must agree — resolveModel's switch, endpointProvider's
+// switch, and the test that pins them — and the first version of this change
+// added the names to one switch and not the other.
+var openAICompatProviders = []string{"openai", "openai-compatible", "kimi", "qwen"}
+
+func isOpenAICompatProvider(name string) bool {
+	return slices.Contains(openAICompatProviders, name)
+}
+
 // endpointProviderNames is the operator-facing list of providers that accept an
 // explicit endpoint. resolveModel and endpointProvider accept the SAME set, so
 // they share one message rather than each carrying a hand-maintained copy that
 // drifts in order and spelling — which is exactly what happened when kimi/qwen
 // were added to both switches.
-const endpointProviderNames = "openai/openai-compatible/kimi/qwen/ollama/ollama-cloud/llama-swap(s)/foreman/anthropic/google"
+//
+// Keep every accepted spelling here, including aliases: the first version of
+// this constant dropped "gemini", so the list written to prevent drift had
+// already drifted from the switches it describes.
+const endpointProviderNames = "openai/openai-compatible/kimi/qwen/ollama/ollama-cloud/" +
+	"llama-swap/llama-swaps/llamaswap/llamaswaps/foreman/anthropic/google/gemini"
 
 // resolveModel builds the review model from the environment. Gadfly is powered
 // by majordomo, so it can target any provider majordomo supports — Ollama
@@ -74,20 +96,19 @@ func resolveModel() (llm.Model, error) {
 	}
 
 	// Endpoint override: construct the provider directly at the given URL.
-	switch provider {
-	case "openai", "openai-compatible", "kimi", "qwen":
-		// kimi (Moonshot) and qwen (Alibaba Model Studio) are majordomo
-		// built-ins that ARE the openai client at a different base URL, so an
-		// explicit GADFLY_BASE_URL for either belongs here. Without these names
-		// the override fell through to default: and errored, even though both
-		// resolve fine on the registry path above — a confusing asymmetry.
-		// The credential here is GADFLY_API_KEY; the built-ins' own
-		// KIMI_API_KEY / QWEN_API_KEY apply only when GADFLY_BASE_URL is unset.
+	// The openai-compat family (openai/openai-compatible/kimi/qwen) is matched
+	// by the shared predicate, not a repeated case list. The credential here is
+	// GADFLY_API_KEY; the built-ins' own KIMI_API_KEY / QWEN_API_KEY apply only
+	// on the registry path above, where GADFLY_BASE_URL is unset.
+	if isOpenAICompatProvider(provider) {
 		opts := []openai.Option{openai.WithBaseURL(baseURL)}
 		if apiKey != "" {
 			opts = append(opts, openai.WithAPIKey(apiKey))
 		}
 		return openai.New(opts...).Model(model)
+	}
+
+	switch provider {
 	case "ollama", "ollama-cloud":
 		opts := []ollama.Option{ollama.WithBaseURL(baseURL)}
 		if apiKey != "" {
@@ -202,7 +223,7 @@ func modelProvider() string {
 //	    plaintext local Ollama (or foreman queue) works:
 //	        GADFLY_ENDPOINT_BIGBOX="ollama|http://192.168.1.50:11434"
 //	        GADFLY_MODEL=bigbox/qwen2.5-coder:7b
-//	    provider is one of ollama/llama-swap(s)/foreman/openai/anthropic/google; "foreman"
+//	    provider is one of endpointProviderNames; "foreman"
 //	    targets a foreman daemon (native Ollama on the wire):
 //	        GADFLY_ENDPOINT_M1="foreman|http://foreman-m1:8080|tok"
 //
@@ -254,6 +275,16 @@ func endpointProvider(name, raw string) (llm.Provider, error) {
 		return nil, fmt.Errorf("missing base URL in %q", raw)
 	}
 
+	// Same shared predicate as resolveModel — the two must accept an identical
+	// set, and hand-copied case lists are how they drifted apart before.
+	if isOpenAICompatProvider(provider) {
+		opts := []openai.Option{openai.WithName(name), openai.WithBaseURL(baseURL)}
+		if key != "" {
+			opts = append(opts, openai.WithAPIKey(key))
+		}
+		return openai.New(opts...), nil
+	}
+
 	switch provider {
 	case "ollama", "ollama-cloud":
 		opts := []ollama.Option{ollama.WithName(name), ollama.WithBaseURL(baseURL)}
@@ -272,16 +303,6 @@ func endpointProvider(name, raw string) (llm.Provider, error) {
 		// its non-streaming degradation. Unlike the HTTPS-only LLM_* foreman://
 		// DSN, the base URL here is verbatim, so a plaintext http:// foreman works.
 		return ollama.Foreman(baseURL, key, ollama.WithName(name)), nil
-	case "openai", "openai-compatible", "kimi", "qwen":
-		// kimi/qwen accepted here for the same reason as in resolveModel: both
-		// majordomo built-ins ARE the openai client at their own base URL, so a
-		// named endpoint pointing at one (a regional Model Studio host, say)
-		// must resolve, not error. The two switches move together.
-		opts := []openai.Option{openai.WithName(name), openai.WithBaseURL(baseURL)}
-		if key != "" {
-			opts = append(opts, openai.WithAPIKey(key))
-		}
-		return openai.New(opts...), nil
 	case "anthropic":
 		opts := []anthropic.Option{anthropic.WithName(name), anthropic.WithBaseURL(baseURL)}
 		if key != "" {