fix: address code review comments on Java doc snippets

[brunoborges]

Summary

Follow-up to #1021 — addresses Copilot code review comments that were filed after the PR was squash-merged.

Fixes (12 files)

• Missing imports: java.util.List, java.util.Map, java.util.Set, java.util.concurrent.CompletableFuture across multiple Java snippets
• Missing setOnPermissionRequest(PermissionHandler.APPROVE_ALL): getting-started (×2), bundled-cli, github-oauth, hooks/index
• Undefined variables: userId and message now declared in github-oauth and backend-services snippets
• Hook Signature section: error-handling.md Java block no longer references an undefined session variable — shows a comment-only note pointing to the full example below
• Consistent permission handler: backend-services uses PermissionHandler.APPROVE_ALL instead of request -> request.allow()

Files changed

File	Fix
docs/auth/byok.md	Add java.util.List import
docs/features/custom-agents.md	Add java.util.List import (2 blocks)
docs/features/hooks.md	Add CompletableFuture + Set imports
docs/features/image-input.md	Add java.util.List import (2 blocks)
docs/features/skills.md	Add java.util.List import (2 blocks)
docs/getting-started.md	Add setOnPermissionRequest (2 blocks)
docs/hooks/error-handling.md	Fix undefined session in Hook Signature
docs/hooks/index.md	Add setOnPermissionRequest
docs/integrations/microsoft-agent-framework.md	Add List + Map imports
docs/setup/backend-services.md	Add userId/message vars, fix permission handler
docs/setup/bundled-cli.md	Add setOnPermissionRequest
docs/setup/github-oauth.md	Add userId var, add setOnPermissionRequest

[Copilot]

Pull request overview

Follow-up documentation fix-up PR that makes the newly-added Java snippets across the docs compile and behave consistently (imports, permission handler wiring, and undefined variables).

Changes:

• Adds missing Java standard-library imports (List, Map, Set, CompletableFuture) across multiple docs snippets.
• Ensures Java snippets consistently set setOnPermissionRequest(PermissionHandler.APPROVE_ALL) in key getting-started/setup examples.
• Fixes snippet correctness issues (e.g., undefined variables; avoids referencing an undefined session in the error-handling “Hook Signature” section).

Show a summary per file

File	Description
docs/auth/byok.md	Adds java.util.List import for List.of(...) usage in Java BYOK snippet.
docs/features/custom-agents.md	Adds java.util.List import; but introduces malformed Java code fencing in one block (see comments).
docs/features/hooks.md	Adds missing CompletableFuture / Set imports for Java hook examples (one snippet still needs SDK imports to be self-contained).
docs/features/image-input.md	Adds java.util.List imports in Java image input snippets.
docs/features/skills.md	Adds java.util.List imports for Java skills examples (including a short config-focused snippet).
docs/getting-started.md	Adds setOnPermissionRequest(PermissionHandler.APPROVE_ALL) to Java getting-started snippets.
docs/hooks/error-handling.md	Reworks the Java “Hook Signature” snippet to avoid referencing an undefined session and points to a full example below.
docs/hooks/index.md	Adds setOnPermissionRequest(PermissionHandler.APPROVE_ALL) to the Java hooks quick start snippet.
docs/integrations/microsoft-agent-framework.md	Adds missing List/Map imports to Java tool example.
docs/setup/backend-services.md	Defines userId/message and switches to PermissionHandler.APPROVE_ALL for consistency.
docs/setup/bundled-cli.md	Adds setOnPermissionRequest(PermissionHandler.APPROVE_ALL) to Java setup snippet.
docs/setup/github-oauth.md	Declares userId and adds setOnPermissionRequest(PermissionHandler.APPROVE_ALL) in the Java OAuth usage snippet.

Copilot's findings

• Files reviewed: 12/12 changed files
• Comments generated: 2