Update remaining documentation files for agents/chatmodes migration

Co-authored-by: TonyCap <162155315+TonyCap@users.noreply.github.com>

Author: Copilot

.github/copilot-instructions.md

@@ -396,7 +396,7 @@ Exceptions:
 - Obtain at least one reviewer acknowledgment of the exception in review comments
 
 References:
-- Chat modes (Developer/Tester) MUST reference this section instead of hardcoding numeric targets.
+- Agents (Developer/Tester) MUST reference this section instead of hardcoding numeric targets.
 - Project-specific overrides, if any, MUST be documented here to remain authoritative.
 
 ---
@@ -423,7 +423,9 @@ NOTE: This section may be removed when used as template, hence the disclaimer
 
 The `.github` directory contains several subdirectories and files that organize configuration, prompts, and instructions for Copilot and other AI agents:
 
-- `chatmodes/`: Contains chat mode configuration files (e.g., `custom-mode.chatmode.md`) that define custom conversational behaviors for Copilot and other agents.
+- `agents/`: Contains agent configuration files (e.g., `Developer.agent.md`) that define custom conversational behaviors for Copilot and other agents. As of October 2025, GitHub renamed "Chat Modes" to "Agents".
+
+- `chatmodes/`: *(Deprecated)* Contains chat mode configuration files (e.g., `Developer.chatmode.md`) for backward compatibility. New development should use the `agents/` directory.
 
 - `instructions/`: Holds instruction files for backend, frontend, and documentation. These guide Copilot and other agents on best practices and project-specific rules. You must apply these instructions to relevant files in the repository.
   - `backend.instructions.md`

CONTRIBUTING.md

@@ -77,7 +77,8 @@ Major changes to existing configurations should be discussed in an issue before
 - **Read SSOT files**: Understand the authoritative guidelines in:
   - `.github/copilot-instructions.md` - Core policies and workflow
   - `.github/instructions/docs.instructions.md` - Documentation standards
-  - `.github/chatmodes/README.md` - Chat mode authoring guide
+  - `.github/agents/README.md` - Agent authoring guide
+  - `.github/chatmodes/README.md` - Chat mode authoring guide (deprecated)
   - `README.md` - Repository overview and SSOT source map
 
 ### 2. Create an Issue (Recommended)
@@ -137,8 +138,8 @@ git checkout -b <type>/<brief-description>
 
 **Examples**:
 
-- `feat: Add security-focused chat mode with threat modeling`
-- `fix: Correct typo in Developer.chatmode.md`
+- `feat: Add security-focused agent with threat modeling`
+- `fix: Correct typo in Developer.agent.md`
 - `docs: Improve explanation of prompting techniques`
 
 #### Adding Comments to Prompts
@@ -253,7 +254,9 @@ plans/                 # Project planning documents
 - Use proper Markdown formatting
 - Avoid emojis in formal documentation (except in this guide for visual clarity)
 
-### Prompts and Chat Modes
+### Prompts and Agents
+
+> **Note:** As of October 2025, GitHub renamed "Chat Modes" to "Agents". New contributions should use the `.github/agents/` directory with the `.agent.md` extension. The `.github/chatmodes/` directory is maintained for backward compatibility.
 
 - Include comprehensive HTML comments
 - Explain prompting techniques explicitly

docs/README.md

@@ -16,9 +16,10 @@ This directory contains all project-related documentation, organized into subdir
 
 ## Writing Documentation Using AI
 
-There are three examples of how to influence and use AI to write documentation in this repository:
+There are four examples of how to influence and use AI to write documentation in this repository:
 
-- [Custom chat modes](../.github/chatmodes/custom-mode.chatmode.md) — Preset conversational configurations that shape Copilot’s behavior and tone during interactive sessions and document generation.
+- [Custom agents](../.github/agents/README.md) — Specialized AI behaviors for tasks like development, testing, and code review. As of October 2025, GitHub renamed "Chat Modes" to "Agents".
+- [Custom chat modes](../.github/chatmodes/README.md) *(deprecated)* — Preset conversational configurations that shape Copilot's behavior and tone during interactive sessions and document generation.
 - [Instructions](../.github/instructions/docs.instructions.md) — Repository-specific rules and constraints (coding standards, workflow, style) that the AI must follow when producing content.
 - [Prompts](../.github/prompts/write-docs.prompt.md) — Reusable prompt templates for generating consistent artifacts (e.g., ADRs, docs, PRDs). See also [write-adr.prompt.md](../.github/prompts/write-adr.prompt.md) and [write-prd.prompt.md](../.github/prompts/write-prd.prompt.md).
 

plans/TODO.md

@@ -1,5 +1,7 @@
 # TODO list
 
+> **Note:** As of October 2025, GitHub renamed "Chat Modes" to "Agents". References to `.github/chatmodes/` and `*.chatmode.md` files in this TODO refer to the deprecated format. The new `.github/agents/` directory uses the `.agent.md` extension. See the migration PR for details.
+
 ## Repository Improvement TODOs
 
 Purpose: Track and review each suggested improvement from `recommendations.md` item by item. Use this as the authoritative checklist for implementation and review.

recommendations.md

@@ -1,7 +1,9 @@
 
 # Repository Configuration & Content Quality Assessment
 
-Scope: Qualitative review of configuration layers (core config, chat modes, instruction files, prompts, planning assets, engineering docs, templates) with redundancy, conflict, risk, and improvement guidance.
+> **Note:** As of October 2025, GitHub renamed "Chat Modes" to "Agents". This document was written before that change and references the deprecated `.github/chatmodes/` directory. The new `.github/agents/` directory uses the `.agent.md` extension. Many recommendations in this document have been addressed.
+
+Scope: Qualitative review of configuration layers (core config, chat modes/agents, instruction files, prompts, planning assets, engineering docs, templates) with redundancy, conflict, risk, and improvement guidance.
 
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