[fix] Apply REMOVE_X_INTERNAL normalizer to nested inline properties

[rc-glean]

Description

This PR fixes a bug where the REMOVE_X_INTERNAL=true normalizer fails to remove the x-internal extension from inline object properties within schemas.

Problem

When REMOVE_X_INTERNAL=true is set, the normalizer correctly removes x-internal from top-level schemas in components/schemas, but fails to process inline object properties.

This causes issues when:

1. A schema is imported cross-file (e.g., admin.yaml imports from chat.yaml)
2. That schema has an inline object property with x-internal: true
3. The inline property has type: object with nested properties

Result: TypeScript generator creates a type reference but no interface definition, causing compilation errors.

Solution

Apply the same x-internal removal logic to normalizeProperties() that already exists in normalizeComponentsSchemas(), ensuring inline properties are handled consistently.

Bug Trigger Conditions

1. ✅ Cross-file import (e.g., admin.yaml imports from chat.yaml)
2. ✅ Schema has an inline object property
3. ✅ That inline property has x-internal: true

Testing

• ✅ Tested with OpenAPI Generator v7.13.0 (all 3,375 tests pass)
• ✅ Verified fix resolves the issue on actual production schema (Glean admin API)
• ✅ No regressions in existing tests

Example

Before (broken):

export interface AgentConfig {
    clientCapabilities?: AgentConfigClientCapabilities; // ❌ Type referenced but not defined
}
// AgentConfigClientCapabilities interface missing!

After (fixed):

export interface AgentConfig {
    clientCapabilities?: AgentConfigClientCapabilities; // ✅ Type referenced
}

export interface AgentConfigClientCapabilities { // ✅ Type IS defined!
    canRenderImages?: boolean;
    artifacts?: ArtifactsClientCapability;
}

[Copilot]

Pull Request Overview

This PR fixes a bug where the REMOVE_X_INTERNAL=true normalizer fails to remove the x-internal extension from inline object properties within schemas, causing TypeScript generation issues when schemas are imported cross-file.

• Applies consistent x-internal removal logic to inline properties
• Prevents TypeScript compilation errors from missing interface definitions
• Ensures cross-file schema imports work correctly with inline object properties

---

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[wing328]

@rc-glean thanks for the PR

can you please review the build failure when you've time?

[rc-glean]

@wing328 this was the first time copilot suggestions in PR recommended a broken fix for me lol c899e9e

Can you retrigger the 4 workflows awaiting approval please?

[wing328]

That's ok.

Did you test the fix locally with the last commit in this branch to confirm it works for your use cases?

[rc-glean]

Thank you. Confirmed the latest commit in this PR: 60cf734, fixes the issue.

Ran the following verification:

## ✅ Fix Verified Against Production Schema

I've tested this fix against Glean's production OpenAPI schema where we encountered this exact bug.

### Test Setup
1. **Schema**: Glean Admin API with cross-file import (`admin.yaml` → `chat.yaml`)
2. **Trigger Condition**: Inline object property with `x-internal: true` inside a cross-file imported schema
3. **Generator Config**: `typescript-fetch` with `--openapi-normalizer REMOVE_X_INTERNAL=true`

### Reproduction
In `chat.yaml`, `AgentConfig` has an inline `clientCapabilities` property marked `x-internal: true`:

```yaml
AgentConfig:
  properties:
    clientCapabilities:
      x-internal: true
      type: object
      properties:
        canRenderImages:
          type: boolean
        artifacts:
          $ref: "#/components/schemas/ArtifactsClientCapability"

When admin.yaml imports this schema, TypeScript generation fails.

Results

❌ Before (v7.16.0 stable)

// AgentConfig references the type...
clientCapabilities?: AgentConfigClientCapabilities;

// ...but the interface is NEVER generated (compilation error)

✅ After (this PR - commit 60cf734)

// Interface is properly generated as AgentConfig_clientCapabilities
export interface AgentConfigClientCapabilities {
    canRenderImages?: boolean;
    artifacts?: ArtifactsClientCapability;
    paper?: PaperConfig;
}

Generator logs confirm proper handling:

[main] INFO o.o.codegen.InlineModelResolver - Inline schema created as AgentConfig_clientCapabilities

Impact

This bug forced us to extract inline schemas into separate top-level schemas as a workaround. With this fix, we can use natural inline object definitions with x-internal flags.

[wing328]

👌

let's give it a try

i think ideally the logic should be done in normalizeSchema. i'll try to do the refactoring later if I can find the time.

thanks again for the contribution.