fix: standardize API URL env var references to TUSK_API_URL (#161)

Author: jy-tan

CONTRIBUTING.md

@@ -115,7 +115,7 @@ Testing auth to Tusk dev:
 - `TUSK_AUTH0_DOMAIN`
 - `TUSK_AUTH0_CLIENT_ID`
 
-By default, if there's a `.tusk/config.yaml` we'll use the API url in that for all Tusk Cloud requests. If no `.tusk/config.yaml` is found, we'll use the default API url (prod API url). You can override this by setting `TUSK_CLOUD_API_URL` in your shell.
+By default, if there's a `.tusk/config.yaml` we'll use the API url in that for all Tusk Cloud requests. If no `.tusk/config.yaml` is found, we'll use the default API url (prod API url). You can override this by setting `TUSK_API_URL` in your shell.
 
 ### Disabling analytics
 

internal/agent/proxy_integration_test.go

@@ -22,7 +22,7 @@ import (
 //   - TUSK_PROXY_TEST_API_KEY: Tusk API key for authentication (does not expire)
 //
 // Optional environment variables:
-//   - TUSK_CLOUD_API_URL: Override the backend URL (defaults to https://api.usetusk.ai)
+//   - TUSK_API_URL: Override the backend URL (defaults to https://api.usetusk.ai)
 //
 // This test uses validate-only mode (x-tusk-validate-only header) to avoid
 // Anthropic API calls and associated costs. It only validates that the system

internal/api/client.go

@@ -71,11 +71,11 @@ const (
 )
 
 // GetBaseURL returns the API base URL with the following priority:
-// 1. TUSK_CLOUD_API_URL environment variable
+// 1. TUSK_API_URL environment variable
 // 2. tusk_api.url from .tusk/config.yaml
 // 3. Default URL (https://api.usetusk.ai)
 func GetBaseURL() string {
-	if envURL := os.Getenv("TUSK_CLOUD_API_URL"); envURL != "" {
+	if envURL := os.Getenv("TUSK_API_URL"); envURL != "" {
 		return envURL
 	}