Fix codegen and handwritten code for @github/copilot 1.0.35 $ref schema changes

---

## Summary

Updates the Java code generator and handwritten SDK/test code to handle the
`@github/copilot` 1.0.35 schema format, which changed from inline nested type
definitions to `$ref` references pointing to `#/definitions/` entries. Without
this fix, regenerated types were missing fields and the build failed.

75 files changed, 616 insertions(+), 1836 deletions(-)

## Changes

### Code generator (`scripts/codegen/java.ts`)

- Added `resolveRef()` helper to dereference `$ref` pointers in JSON schemas.
- Added `pendingStandaloneTypes` map to collect types referenced via `$ref` and
  generate them as top-level Java files instead of nested records.
- Added `generatePendingStandaloneTypes()`, `generateStandaloneEnum()`, and
  `generateStandaloneRecord()` to emit the new standalone types.
- Updated all property/field generation paths to resolve `$ref` before
  inspecting type, enum, or nested-object shapes.

### Regenerated files (`src/generated/java/`)

- ~65 generated source files updated — nested inner records/enums replaced by
  standalone types (e.g. `McpServer`, `Plugin`, `Skill`, `Tool`, `Model`,
  `AccountQuotaSnapshot`, `DiscoveredMcpServer`, `UIElicitationSchema`,
  `UIElicitationResponseAction`, `ModelCapabilitiesOverride`, etc.).
- Several numeric fields changed from `double` to `Long` (`PingResult`,
  `SessionShellExecParams`, model capability limits).
- New RPC API class `ServerMcpConfigApi` and `SessionPermissionsApi` added.

### Handwritten source (`CopilotSession.java`)

- Updated all type references from old nested types to new standalone types
  (e.g. `SessionMcpListResultServersItem` → `McpServer`).

### Test files (5 files)

- **`GeneratedRpcRecordsCoverageTest.java`** — Replaced all nested type
  references with standalone types; fixed `double` → `Long` constructors.
- **`GeneratedEventTypesCoverageTest.java`** — Updated event type name set.
- **`GeneratedRpcApiCoverageTest.java`** — Updated `workspace` → `workspaces`,
  added `SessionLogLevel`, new API classes.
- **`RpcWrappersTest.java`** — `session.workspace` → `session.workspaces`.
- **`SessionEventDeserializationTest.java`** — Updated JSON keys for
  `compactionTokensUsed` (`input` → `inputTokens`, `output` → `outputTokens`,
  `cachedInput` → `cacheReadTokens`).

### Dependency bump

- `@github/copilot` 1.0.24 → 1.0.35 in `scripts/codegen/package.json`.
- **`.github/workflows/update-copilot-dependency.yml`** — After codegen and PR creation, `mvn verify` is run. On failure, the agentic fix workflow is triggered. Includes a polling loop that waits for the fix to complete and runs a final verification.

## Design

The pipeline follows a two-workflow pattern:

1. **Trigger workflows** (`codegen-check.yml`, `update-copilot-dependency.yml`) detect failures and dispatch the agentic fix.
2. **Fix workflow** (`codegen-agentic-fix.lock.yml`) runs under gh-aw guardrails with scoped permissions, network firewall, and MCP gateway. It checks out the branch, reproduces the failure, applies fixes to handwritten code only, and pushes via `push-to-pull-request-branch` safe-output.

Key constraints enforced on the agent:
- Never modify `src/generated/java/`, `pom.xml`, `scripts/codegen/`, or `.github/`
- Maximum 3 fix attempts before escalating via PR comment
- Must run `mvn spotless:apply` before committing
- Only pushes if `mvn verify` passes

## Testing

- All workflow files pass `actionlint` with zero errors
- The `codegen-agentic-fix.lock.yml` was successfully compiled by `gh aw compile v0.68.3`
- End-to-end testing will occur when this PR and #94 are both merged — Dependabot PR #99 (bump `@github/copilot` 1.0.24 → 1.0.35) already exists and its Codegen Check is failing as expected

Author: edburns

scripts/codegen/java.ts

@@ -7,7 +7,7 @@
     "generate:java": "tsx java.ts"
   },
   "dependencies": {
-    "@github/copilot": "1.0.24",
+    "@github/copilot": "^1.0.35",
     "json-schema": "^0.4.0",
     "tsx": "^4.20.6"
   }