feat(agents): add .DCP shorthand command and dcp skill

.DCP = Document, Commit, Push — updates in-repo docs and .labyricorn
devlog records for recent milestones, validates, commits, and pushes
to origin/main. Skill defined at .agents/skills/dcp/SKILL.md.
Command documented in root AGENTS.md shorthand commands section.

.agents/skills/dcp/SKILL.md

@@ -0,0 +1,154 @@
+---
+name: dcp
+description: >
+  Triggered by the user command ".DCP". Updates in-repo documentation and
+  .labyricorn devlog records to reflect recent work, then commits and pushes
+  all changes to origin/main (production). Run this skill whenever the user
+  issues ".DCP".
+---
+
+# DCP — Document, Commit, Push
+
+The user command `.DCP` means: bring documentation and Labyricorn publishing
+records up to date with the current state of the codebase, then commit
+everything and push to production (`origin/main`).
+
+Read this file fully before starting. Also read:
+- `AGENTS.md` (root) — communication and authorization rules
+- `.labyricorn/AGENTS.md` — publishing boundaries and content contract
+- `.labyricorn/devlog/AGENTS.md` — devlog entry format and safety rules
+- `.labyricorn/project/AGENTS.md` — project record rules
+
+---
+
+## Phase 1 — Orient
+
+1. Run `git log --oneline -10` to see the most recent commits since the last
+   `.DCP` run (look for the previous "docs:" or "devlog:" commit to find the
+   boundary).
+2. Run `git diff --stat HEAD` (or `git status`) to see any uncommitted changes.
+3. Identify what changed: new features, bug fixes, refactors, renamed
+   files, config changes, dependency updates, etc.
+4. Note today's date (`YYYY-MM-DD`) and the **full 40-character commit SHA**
+   of the most recent relevant commit (`git rev-parse HEAD`).
+
+---
+
+## Phase 2 — Update In-Repo Documentation
+
+Update any documentation files that are stale relative to the current
+implementation. This includes:
+
+- `README.md` — feature lists, setup steps, API examples, port numbers,
+  binary names, MCP config snippets, environment variable names
+- `CHANGELOG.md` — add an `[Unreleased]` entry or append to the current one
+  summarizing what changed (use the draft-release-notes skill format if
+  already in use)
+- `docs/` content — any `.mdx` / `.md` files whose prose contradicts or
+  omits the current implementation
+- `backend/README.md` — if API or server behavior changed
+- Any other doc whose claims are now incorrect
+
+**Rules:**
+- Only update what is actually stale. Do not rewrite correct documentation.
+- Do not alter application source code as part of a `.DCP` run.
+- After edits, run `git diff --check` to confirm no whitespace errors.
+
+---
+
+## Phase 3 — Update .labyricorn Devlog
+
+Create or update devlog entries for the milestones reached since the last
+`.DCP`. Follow `.labyricorn/devlog/AGENTS.md` strictly.
+
+### Entry location
+`devlog/<stable-slug>/contents.lr` — one entry per meaningful milestone.
+If multiple milestones occurred since the last `.DCP`, create multiple entries.
+
+### Required fields (all mandatory)
+```
+_model: devlog-entry
+schema_version: 1
+title: <Human-readable title>
+date: <YYYY-MM-DD of source_commit>
+author: Labyricorn
+summary: <One-sentence summary suitable for a chronological listing>
+tags: <Comma-separated display labels, e.g. tts, ui, backend, mcp, release>
+source_commit: <Full 40-character lowercase commit SHA>
+---
+body:
+
+<Markdown prose — explain the milestone, why it mattered, what changed.
+Do NOT merely expand a commit message. Do NOT invent results, user feedback,
+or completion claims. Distinguish design from shipping behavior.
+Link to the commit using the repo HTTPS URL.>
+```
+
+### Update the devlog index
+Ensure `.labyricorn/devlog/contents.lr` lists any new entry slug in its
+`entries` field (if the schema uses an index).
+
+### Update project record if needed
+If the project status, summary, or description at
+`.labyricorn/project/contents.lr` is stale, update it. Ask before changing
+`project_id`, `repository_url`, `default_branch`, or `author`.
+
+### Validate
+Run:
+```
+python devlog_editor.py --validate
+```
+Fix any validation errors before proceeding. If the script is unavailable,
+manually verify all required fields are present in every touched record.
+
+---
+
+## Phase 4 — Commit
+
+Stage only the documentation and `.labyricorn/` changes:
+
+```
+git add README.md CHANGELOG.md docs/ .labyricorn/
+# Add any other doc files that were updated
+git add <any other updated doc files>
+```
+
+Do **not** stage unrelated application source changes unless the user
+explicitly included them in the current session's work.
+
+Run `git diff --check --cached` to confirm no whitespace errors in staged
+files.
+
+Commit with a message in this format:
+
+```
+docs: update documentation and devlog for <brief description>
+
+- Updated README.md: <what changed>
+- Updated CHANGELOG.md: <what changed>
+- Added devlog entry '<slug>': <one-line summary>
+- Updated project record: <what changed> (if applicable)
+```
+
+---
+
+## Phase 5 — Push
+
+```
+git push
+```
+
+This pushes to `origin/main` (production). Confirm the push succeeded and
+report the final commit SHA and push status to the user.
+
+---
+
+## Handoff report
+
+After completing all phases, tell the user:
+1. Which documentation files were updated and what changed
+2. Which devlog entries were created or updated (with their slugs and dates)
+3. The commit SHA and message
+4. Push status (succeeded / failed + error)
+5. Any items that need follow-up (e.g. validation warnings, stale docs
+   that need more information from the user before they can be updated)

AGENTS.md

@@ -45,4 +45,13 @@ scoped `AGENTS.md` files before making changes.
 - Alternatively, launch the graphical editor with `python devlog_editor.py` for
   interactive management of devlog entries and publishing status.
 - Run `git diff --check` and review diffs carefully before staging or committing.
-- At handoff, summarize files changed, validation performed, and any next steps.
+- At handoff, summarize files changed, validation performed, and any next steps.
+
+## Shorthand commands
+
+- `.DCP` — **Document, Commit, Push.** When the user issues `.DCP`, read and
+  execute the `.agents/skills/dcp/SKILL.md` skill in full. This means:
+  update any stale in-repo documentation (README, CHANGELOG, docs/), write or
+  update `.labyricorn/` devlog entries for recent milestones, validate with
+  `python devlog_editor.py --validate`, commit the documentation and devlog
+  changes, and push to `origin/main`.