Add brag-sheet skill — turn forgotten work into review bullets (#1428)

* Add brag-sheet skill — work impact writer for performance reviews

* polish: improve skill with frontmatter, fallbacks, cross-platform guidance

* improve skill with routing table, anti-patterns, evidence ladder, gotchas

* trim skill to reduce token count, run npm start to update docs

docs/README.skills.md

@@ -67,6 +67,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-skills) for guidelines on how to
 | [batch-files](../skills/batch-files/SKILL.md)<br />`gh skills install github/awesome-copilot batch-files` | Expert-level Windows batch file (.bat/.cmd) skill for writing, debugging, and maintaining CMD scripts. Use when asked to "create a batch file", "write a .bat script", "automate a Windows task", "CMD scripting", "batch automation", "scheduled task script", "Windows shell script", or when working with .bat/.cmd files in the workspace. Covers cmd.exe syntax, environment variables, control flow, string processing, error handling, and integration with system tools. | `assets/executable.txt`<br />`assets/library.txt`<br />`assets/task.txt`<br />`references/batch-files-and-functions.md`<br />`references/cygwin.md`<br />`references/msys2.md`<br />`references/tools-and-resources.md`<br />`references/windows-commands.md`<br />`references/windows-subsystem-on-linux.md` |
 | [bigquery-pipeline-audit](../skills/bigquery-pipeline-audit/SKILL.md)<br />`gh skills install github/awesome-copilot bigquery-pipeline-audit` | Audits Python + BigQuery pipelines for cost safety, idempotency, and production readiness. Returns a structured report with exact patch locations. | None |
 | [boost-prompt](../skills/boost-prompt/SKILL.md)<br />`gh skills install github/awesome-copilot boost-prompt` | Interactive prompt refinement workflow: interrogates scope, deliverables, constraints; copies final markdown to clipboard; never writes code. Requires the Joyride extension. | None |
+| [brag-sheet](../skills/brag-sheet/SKILL.md)<br />`gh skills install github/awesome-copilot brag-sheet` | Turn vague "what did I do?" into evidence-backed impact statements for performance reviews, self-reviews, promotion packets, and weekly updates. Uniquely mines Copilot CLI session logs to reconstruct forgotten work, plus git commits and GitHub PRs. Enforces a 3-part impact contract (action → result → evidence). Works standalone with zero dependencies. Trigger for: "brag", "log work", "what did I do", "backfill my work history", "performance review", "self-review", "self assessment", "write impact statement", "review prep", "promo packet", "promotion case", "weekly update", "status report", "accomplishments", "what did I ship", "I forgot to log my work", "summarize my work", "track my wins", "what should I highlight", "end of half", "career growth", "work journal", or any request to document, summarize, or organize work accomplishments. | None |
 | [breakdown-epic-arch](../skills/breakdown-epic-arch/SKILL.md)<br />`gh skills install github/awesome-copilot breakdown-epic-arch` | Prompt for creating the high-level technical architecture for an Epic, based on a Product Requirements Document. | None |
 | [breakdown-epic-pm](../skills/breakdown-epic-pm/SKILL.md)<br />`gh skills install github/awesome-copilot breakdown-epic-pm` | Prompt for creating an Epic Product Requirements Document (PRD) for a new epic. This PRD will be used as input for generating a technical architecture specification. | None |
 | [breakdown-feature-implementation](../skills/breakdown-feature-implementation/SKILL.md)<br />`gh skills install github/awesome-copilot breakdown-feature-implementation` | Prompt for creating detailed feature implementation plans, following Epoch monorepo structure. | None |