feat: add flowstudio-power-automate-debug and flowstudio-power-automate-build skills (#899)

* feat: add flowstudio-power-automate-debug and flowstudio-power-automate-build skills

Two companion skills for the FlowStudio Power Automate MCP server:

- flowstudio-power-automate-debug: Debug workflow for failed Power Automate cloud flow runs
- flowstudio-power-automate-build: Build & deploy flows from natural language descriptions

Both require a FlowStudio MCP subscription: https://flowstudio.app
These complement the existing flowstudio-power-automate-mcp skill (merged in PR #896).

* fix: address all review comments — README, cross-refs, response shapes, step numbering

- Add skills to docs/README.skills.md (fixes validate-readme CI check)
- Update cross-skill references to use flowstudio- prefix (#1, #4, #7, #9)
- Fix get_live_flow_run_action_outputs: returns array, index [0] (#2, #3)
- Renumber Step 6→5, Step 7→6 — remove gap in build workflow (#8)
- Fix connectionName note: it's the key, not the GUID (#10)
- Remove invalid arrow function from Filter array expression (#11)

* feat: add flowstudio-power-automate plugin bundling all 3 skills

Plugin bundles:
- flowstudio-power-automate-mcp (core connection & CRUD)
- flowstudio-power-automate-debug (debug failed runs)
- flowstudio-power-automate-build (build & deploy flows)

Install: copilot plugin install flowstudio-power-automate@awesome-copilot

Per @aaronpowell's suggestion in review.

.github/plugin/marketplace.json

@@ -113,6 +113,12 @@
       "description": "Task Researcher and Task Planner for intermediate to expert users and large codebases - Brought to you by microsoft/edge-ai",
       "version": "1.0.0"
     },
+    {
+      "name": "flowstudio-power-automate",
+      "source": "flowstudio-power-automate",
+      "description": "Complete toolkit for managing Power Automate cloud flows via the FlowStudio MCP server. Includes skills for connecting to the MCP server, debugging failed flow runs, and building/deploying flows from natural language.",
+      "version": "1.0.0"
+    },
     {
       "name": "frontend-web-dev",
       "source": "frontend-web-dev",