docs: update glossary - daily scan 2026-04-14 (#26189)

Author: github-actions[bot]

docs/src/content/docs/reference/glossary.md

@@ -103,6 +103,10 @@ Three additional fields extend integrity filtering beyond the level threshold: `
 
 Controls full Data Integrity and Flow Control (DIFC) proxy enforcement. When `tools.github.min-integrity` is configured, the compiler injects proxy steps around the agent job that enforce integrity-level isolation at the network boundary. The proxy is **enabled by default** — set `tools.github.integrity-proxy: false` to disable it and rely solely on MCP gateway-level filtering. Filtered content is recorded as `DIFC_FILTERED` events in `gateway.jsonl` for later inspection. See [Integrity Filtering](/gh-aw/reference/integrity/).
 
+### Integrity Reactions (`features.integrity-reactions`)
+
+A feature flag that enables GitHub reactions (👍, ❤️, 👎, 😕) to promote or demote content past the integrity filter. When `integrity-reactions: true` is set, trusted members can add a reaction to an issue or comment to elevate its integrity to `approved` (endorsement reactions) or demote it to `none` (disapproval reactions) — without modifying labels. Enabling this flag automatically activates `cli-proxy` mode, which is required to identify reaction authors at the network boundary. Available from gh-aw v0.68.2. See [Maintaining Repos](/gh-aw/guides/maintaining-repos/#reactions-as-trust-signals).
+
 ### Status Comment
 
 A comment posted on the triggering issue or pull request that shows workflow run status (started and completed). Configured via `status-comment: true` in `safe-outputs`. Defaults to `true` for `slash_command` and `label_command` triggers; must be explicitly enabled for other trigger types. Set `status-comment: false` to disable. Not automatically bundled with `ai-reaction` — each must be configured independently.
@@ -233,7 +237,7 @@ Named shorthand references to predefined domain sets used in `network.allowed` a
 
 ### Engine
 
-The AI system that powers the agentic workflow - essentially "which AI to use" to execute workflow instructions. GitHub Agentic Workflows supports multiple engines, with GitHub Copilot as the default.
+The AI system that powers the agentic workflow - essentially "which AI to use" to execute workflow instructions. GitHub Agentic Workflows supports four engines: **Copilot** (default), **Claude**, **Codex**, and **Gemini**. Set `engine:` in frontmatter to choose; omit it to use Copilot. See [AI Engines Reference](/gh-aw/reference/engines/).
 
 ### Enterprise API Endpoint (`api-target`)
 
@@ -271,7 +275,7 @@ See [Engines Reference](/gh-aw/reference/engines/).
 
 ### Feature Flags (`features:`)
 
-A frontmatter section that enables experimental or optional compiler and runtime behaviors as key-value pairs. Feature flags provide controlled access to new capabilities before they become defaults or are fully stabilized. Common flags include `action-mode` (controls how custom action references are compiled), `copilot-requests` (enables GitHub Actions token authentication for Copilot), and `mcp-gateway` (enables the MCP gateway proxy). See [Frontmatter Reference](/gh-aw/reference/frontmatter/#feature-flags-features).
+A frontmatter section that enables experimental or optional compiler and runtime behaviors as key-value pairs. Feature flags provide controlled access to new capabilities before they become defaults or are fully stabilized. Common flags include `action-mode` (controls how custom action references are compiled), `copilot-requests` (enables GitHub Actions token authentication for Copilot), `mcp-gateway` (enables the MCP gateway proxy), `integrity-reactions` (enables reaction-based integrity promotion and demotion), and `cli-proxy` (enables CLI proxy mode for integrity enforcement at the network boundary). See [Frontmatter Reference](/gh-aw/reference/frontmatter/#feature-flags-features).
 
 ### Fuzzy Scheduling