Document canceled job recovery in helix skill

Canceled AzDO jobs (typically from timeouts) still have pipeline
artifacts containing binlogs. The SendToHelix.binlog contains Helix
job IDs that can be queried directly to recover actual test results.

Discovered while investigating PR #124125 where a 3-hour timeout
caused a WasmBuildTests job to be canceled, but all 226 Helix work
items had actually passed.

Author: lewing

.github/skills/azdo-helix-failures/SKILL.md

@@ -111,10 +111,25 @@ The script provides a recommendation at the end, but this is based on heuristics
 - **Manual investigation steps**: See [references/manual-investigation.md](references/manual-investigation.md)
 - **AzDO/Helix details**: See [references/azdo-helix-reference.md](references/azdo-helix-reference.md)
 
+## Recovering Results from Canceled Jobs
+
+Canceled jobs (typically from timeouts) often still have useful artifacts. The Helix work items may have completed successfully even though the AzDO job was killed while waiting to collect results.
+
+**To investigate canceled jobs:**
+
+1. **Download build artifacts**: Use the AzDO artifacts API to get `Logs_Build_*` pipeline artifacts for the canceled job. These contain binlogs even for canceled jobs.
+2. **Extract Helix job IDs**: Use the binlog MCP server to load the `SendToHelix.binlog` and search for `"Sent Helix Job"` messages. Each contains a Helix job ID.
+3. **Query Helix directly**: For each job ID, query `https://helix.dot.net/api/jobs/{jobId}/workitems?api-version=2019-06-17` to get actual pass/fail results.
+
+**Example**: A `browser-wasm windows WasmBuildTests` job was canceled after 3 hours. The binlog (truncated) still contained 12 Helix job IDs. Querying them revealed all 226 work items passed — the "failure" was purely a timeout in the AzDO wrapper.
+
+**Key insight**: "Canceled" ≠ "Failed". Always check artifacts before concluding results are lost.
+
 ## Tips
 
 1. Read PR description and comments first for context
 2. Check if same test fails on main branch before assuming transient
 3. Look for `[ActiveIssue]` attributes for known skipped tests
 4. Use `-SearchMihuBot` for semantic search of related issues
 5. Binlogs in artifacts help diagnose MSB4018 task failures
+6. Use the binlog MCP server (`binlog.mcp`) to search binlogs for Helix job IDs, build errors, and properties