azure-devops-cli: handle long comments on Windows (#2061) (#2140)

* azure-devops-cli: handle long comments on Windows (#2061)

On Windows 'az' is a cmd.exe batch wrapper capped at ~8191 characters,
so a long --discussion / --description value silently truncates or
fails. Document three verified ways out so the coding agent doesn't
waste 3-5 turns falling back to raw token retrieval and REST:

1. azps.ps1 in PowerShell on Windows. Same Azure CLI, invoked through
   the Python entry point with no cmd.exe length cap. Pair with
   'Get-Content -Raw' so the body lives in a variable, not on the
   command line.

2. Native --file-path flags where Azure CLI offers them. Applies to
   'az devops wiki page create' and 'az devops wiki page update', both
   documented with --encoding.

3. 'az devops invoke --in-file' as the universal escape hatch for
   commands with no --file-path (work-item --discussion, PR
   --description). Documented example posts to the work item
   comments REST endpoint with api-version 7.0-preview.3.

The earlier draft suggested the Azure CLI '@<file>' convention as a
generic substitute for inline string args. The official docs only
document it for JSON parameters and the CLI source uses
'get_file_json' specifically, so the claim is removed and replaced
with an explicit warning not to rely on it for plain string args.

Files touched:
- skills/azure-devops-cli/SKILL.md: new 'Posting long comments on
  Windows' section with shell-detection table and three verified
  options.
- skills/azure-devops-cli/references/boards-and-iterations.md: short
  pointer at each --discussion example back to SKILL.md, plus an
  inline PowerShell snippet.

Closes #2061.

* azure-devops-cli: move long-comments guidance to reference file (#2061 review)

aaronpowell asked for the Windows long-comments section to live as a
reference file rather than inline in SKILL.md, so the token weight
isn't always loaded into the agent's context.

- Move the "Posting long comments on Windows" section to a new
  references/long-comments-on-windows.md verbatim.
- Strip the section from SKILL.md (56 fewer lines in the always-loaded
  surface).
- Add the new file to the Reference Files table in SKILL.md with a
  one-line "when to read" hint covering --discussion, --description,
  and --content failures on Windows.
- Update the two pointer comments in references/boards-and-iterations.md
  to point at the new reference file instead of the SKILL.md section.

docs/README.skills.md regenerated by 'npm run build' to pick up the
new reference file in the skill's bundled assets column.

skills/azure-devops-cli/references/boards-and-iterations.md

@@ -56,6 +56,10 @@ az boards work-item create \
   --type Bug \
   --discussion "Initial investigation completed"
 
+# For a long --discussion body on Windows, see references/long-comments-on-windows.md.
+# Short version: use azps.ps1 in PowerShell, or fall back to 'az devops invoke'
+# with --in-file when no native --file-path flag is available.
+
 # Open in browser after creation
 az boards work-item create --title "Bug" --type Bug --open
 ```
@@ -85,6 +89,14 @@ az boards work-item update \
   --id {work-item-id} \
   --discussion "Work in progress"
 
+# Long comment on Windows: read the body into a PowerShell variable and call
+# azps.ps1 instead of az.cmd, or fall back to 'az devops invoke' with --in-file.
+# Full guidance in references/long-comments-on-windows.md.
+#
+# PowerShell example:
+#   $body = Get-Content -Raw .\comment.md
+#   azps.ps1 boards work-item update --id 1234 --discussion $body
+
 # Update with custom fields
 az boards work-item update \
   --id {work-item-id} \