fix: remove Firefox from the supported browser types

[giordano-lucas]

Notte runs Chromium-family browsers only. Starting a session with --browser-type firefox is rejected by the API:

Value error, Firefox sessions are not supported.
Please use 'chromium' or 'chrome' as `browser_type`.

The CLI still advertised it in several places.

Changes

Where	Was	Now
README.md feature list	"headless or headed Chrome/Firefox"	"headless or headed Chromium/Chrome"
README.md flag line	--browser-type chromium|chrome|firefox	--browser-type chromium|chrome
scripts/gen-flags/types.go	"Can be chromium, chrome or firefox."	"Supported values are chromium and chrome."
internal/validate/validate.go	accepts chromium|firefox|webkit	accepts chromium|chrome + legacy aliases

The gen-flags override had drifted: the generated flag help already reads "Supported values are chromium and chrome. chrome-nightly and chrome-turbo are legacy aliases for chrome", but the override source it is generated from still mentioned Firefox, so it would come back the next time that override applies.

validate.Browser was wrong in both directions

valid := map[string]bool{
    "chromium": true,
    "firefox":  true,   // rejected by the API
    "webkit":   true,   // never supported
}
// ...and "chrome", which IS valid, was rejected

That's Playwright's browser set, not Notte's. It now accepts chromium and chrome plus the chrome-nightly / chrome-turbo legacy aliases, and the error message names the real options.

Two things deliberately left alone

validate.Browser is dead code. ValidateBrowser is referenced only by its own unit test — never wired to --browser-type, which is why an invalid value reaches the API today rather than failing locally. Wiring it up would give a cleaner client-side error and save a round trip, but it changes behaviour and would stop TestErrorParsing_InvalidBrowserType / TestErrorParsing_ValidationErrorContainsDetails exercising the API error path, since they use an invalid browser type as their trigger. Happy to do it in a follow-up if you want it — it needs those tests re-pointed at a different invalid input.

internal/api/client.gen.go still has SessionResponseBrowserTypeFirefox. It is generated from the OpenAPI spec and untouched here. Removing it means dropping firefox from the spec's browser_type Literal — worth doing, since the API currently accepts it through the Literal only to reject it in a second validator, which is what produces the slightly confusing two-layer error above.

Testing

• go build ./..., go vet ./..., gofmt -l clean
• go test ./internal/... — all 10 packages pass
• Unit tests updated to assert Firefox and WebKit are now rejected and that chrome and its aliases are accepted
• tests/integration/errors_test.go no longer lists firefox among the browser names it expects to see in a validation error

Verified against prod that --browser-type firefox is rejected end to end.

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR aligns browser-type validation and documentation with the Chromium-only backend while retaining two legacy Chrome aliases.

• Rejects Firefox and WebKit while accepting Chromium, Chrome, and legacy Chrome aliases.
• Updates README and generator override text to remove Firefox.
• Updates unit and integration coverage for the corrected browser set.

Confidence Score: 5/5

The PR appears safe to merge with no actionable defects identified.

The validation, generated-help source, documentation, and tests consistently remove Firefox while preserving API-defined legacy Chrome aliases.

Important Files Changed

Filename	Overview
internal/validate/validate.go	Corrects the accepted browser set and validation error to match the backend contract.
scripts/gen-flags/types.go	Removes Firefox from the fallback browser-type help text used by flag generation.
internal/validate/validate_test.go	Covers supported Chromium-family values and rejection of Firefox and WebKit.
tests/integration/errors_test.go	Updates integration expectations so Firefox is no longer treated as a valid browser suggestion.
README.md	Updates feature and flag documentation to advertise Chromium and Chrome rather than Firefox.

_{Reviews (1): Last reviewed commit: "fix: remove Firefox from the supported b..." | Re-trigger Greptile}