feat(skills): separate public and contributor workflows (NVIDIA#2899)

* feat(skills): separate public and contributor workflows

Closes NVIDIA#2736

Publish the four user-facing OpenShell skills from the top-level skills directory, mark contributor workflows internal, and update portability guidance, validation, and documentation.

Signed-off-by: Johnny Greco <jogreco@nvidia.com>

* docs(skills): clarify public skill audit scope

Signed-off-by: Johnny Greco <jogreco@nvidia.com>

* docs(skills): use markdown documentation links

Signed-off-by: Johnny Greco <jogreco@nvidia.com>

* docs(skills): align public and contributor guidance

Signed-off-by: Johnny Greco <jogreco@nvidia.com>

---------

Signed-off-by: Johnny Greco <jogreco@nvidia.com>

Author: johnnygreco

.agents/skills/build-from-issue/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: build-from-issue
 description: Given a GitHub issue number, plan and implement the work described in the issue. Supports direct user requests and unattended queue processing through the `agent:*` workflow labels. Includes tests, documentation updates, and PR creation. Trigger keywords - build from issue, implement issue, work on issue, build issue, start issue.
+metadata:
+  internal: true
 ---
 
 # Build From Issue

.agents/skills/build-openshell-mxc-windows/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: build-openshell-mxc-windows
 description: Maintain and validate OpenShell's build-only Windows MSVC lane for x64 and ARM64. Use when working on Windows compilation, `windows:*` mise tasks, unsupported Windows compute-driver contracts, or Windows build reports. This skill does not implement Docker, Kubernetes, Podman, VM, MXC driver, policy translation, MSI, service, or supervisor runtime support on Windows.
+metadata:
+  internal: true
 ---
 
 # Build OpenShell-MXC for Windows

.agents/skills/create-github-issue/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: create-github-issue
 description: Create GitHub issues using the gh CLI. Use when the user wants to create a new issue, report a bug, request a feature, or create a task in GitHub. Trigger keywords - create issue, new issue, file bug, report bug, feature request, github issue.
+metadata:
+  internal: true
 ---
 
 # Create GitHub Issue

.agents/skills/create-github-pr/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: create-github-pr
 description: Create GitHub pull requests using the gh CLI. Use when the user wants to create a new PR, submit code for review, or open a pull request. Trigger keywords - create PR, pull request, new PR, submit for review, code review.
+metadata:
+  internal: true
 ---
 
 # Create GitHub Pull Request

.agents/skills/create-rfc/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: create-rfc
 description: Create OpenShell RFC proposals in rfc/ from a design request. Use when the user asks to write, draft, start, create, or update an RFC, Request for Comments, architecture proposal, API proposal, process proposal, or cross-cutting design proposal that should follow the OpenShell RFC process and template.
+metadata:
+  internal: true
 ---
 
 # Create RFC

.agents/skills/create-spike/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: create-spike
 description: Investigate a plain-language problem description by deeply exploring the codebase, then create a structured GitHub issue with technical findings. Prequel to build-from-issue — maps vague ideas to concrete, buildable issues. Trigger keywords - spike, investigate, explore, research issue, technical investigation, create spike, new spike, feasibility, codebase exploration.
+metadata:
+  internal: true
 ---
 
 # Create Spike

.agents/skills/fix-security-issue/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: fix-security-issue
 description: Implement a fix for a reviewed security issue. Takes a directly requested issue number or scans for issues labeled `topic:security` and `agent:implementation-requested`. Reads the security review from the issue comments and implements the remediation plan. Trigger keywords - fix security issue, remediate security, implement security fix, patch vulnerability.
+metadata:
+  internal: true
 ---
 
 # Fix Security Issue

.agents/skills/helm-dev-environment/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: helm-dev-environment
 description: Start up, tear down, and configure the local Kubernetes development environment for OpenShell. Uses k3d (Docker-backed k3s) + Skaffold + Helm. Covers cluster lifecycle, optional add-ons (Keycloak OIDC, Envoy Gateway), HA testing, and port mappings. Trigger keywords - local k8s, local cluster, k3d, skaffold, helm dev, start cluster, stop cluster, tear down cluster, delete cluster, create cluster, helm:k3s, helm:skaffold, local dev environment, dev cluster, k8s dev, envoy gateway local, keycloak local, high availability, HA.
+metadata:
+  internal: true
 ---
 
 # Helm Dev Environment

.agents/skills/launch-openshell-gator/SKILL.md

@@ -1,6 +1,8 @@
 ---
 name: launch-openshell-gator
 description: Launch and supervise OpenShell gator agents. Use when starting gator on issues or PRs, checking gator sandboxes, building the gator sandbox image, restarting stuck gators, inspecting gator logs, or experimenting with gator harness/model overrides. Trigger keywords - launch gator, start gator, run gator, gator sandbox, supervised gator, gator logs, restart gator.
+metadata:
+  internal: true
 ---
 
 # Launch OpenShell Gator