Add DeepSeek Harness as a supported skills provider (#746)

* Add DeepSeek Harness as a supported skills provider

npx impeccable install now detects ~/.dsh (or $DSH_HOME when it sits
under home) and installs into ~/.dsh/skills, the user-level skill root
DeepSeek Harness scans, with project-level .dsh/skills on the same
layout as other providers. Aliases: dsh, deepseek, deepseek-harness.

Engine: PROVIDER_DIRS / aliases / display / input order / global hint,
$DSH_HOME-aware user skills dir, provider id resolution from the skill
dir, pin harness dirs, bundle path normalization for hashing.

Build: dsh transformer target emitting the frontmatter DeepSeek Harness
reads (user-invocable, license, compatibility, metadata; unknown keys
are ignored there) with no emitHooks (DSH hooks are in-process plugins,
not on-disk manifests) and no agentFormat (no documented on-disk
subagent format); placeholders (AGENTS.md config file, ask_user_question
tool, / command prefix), provider block tags, universal README entry.

Docs: HARNESSES.md row and frontmatter column, CLI-CONTRACT constants,
README/DEVELOP/AGENTS provider lists.

Validation: cargo test --workspace; node scripts/run-tests.mjs core
(138 pass); bun run build (19 providers, dist/dsh artifact verified);
engine smoke against a fake HOME with a local bundle: install
--providers=dsh --scope=global, auto-detected install, and update all
resolve the .dsh provider.

Generated provider output intentionally omitted per repo policy; the
sync workflow regenerates tracked .dsh/skills after merge.

Prepared with AI assistance (DeepSeek Harness coding agent).

* Address review: DSH_HOME-only detection, generated-output pathspecs

- Detect DeepSeek Harness through the resolved $DSH_HOME (fallback
  ~/.dsh) instead of gating on a fixed ~/.dsh path, so a DSH_HOME-only
  setup is offered by a provider-less install; generalize the two
  env-relocated config-dir hints (OpenCode, DSH) into one shared probe.
- Add .dsh to the sync workflow's GENERATED_PATHS and CI's generated
  drift check so the tracked .dsh/skills payload is committed and
  validated.
- Cover both behaviors: new install_detection_tests (DSH_HOME-only,
  default ~/.dsh, refused outside-home override) and a CLI-CONTRACT
  note on the resolved detection path.

Validation: cargo test --workspace; node scripts/run-tests.mjs core
(138 pass); engine smoke: DSH_HOME-only fake HOME installs globally
into the resolved skills dir.

Prepared with AI assistance (DeepSeek Harness coding agent).

* Fix DeepSeek Harness home paths on Windows

Use native relative-path containment, cover case and drive boundaries, and verify relocated global install/update without changing project skills. Add DSH output coverage and correct the install documentation.

AI assistance: Codex, under pbakaus maintainer direction.

* Document the CLI limit on external DSH homes

Clarify that outside-home manual copies are not detected or updated by the CLI.

AI assistance: Codex, under pbakaus maintainer direction.

---------

Co-authored-by: Paul Bakaus <paul.bakaus@gmail.com>

scripts/build.js

@@ -641,6 +641,7 @@ This folder contains skills for all supported tools:
 
   .cursor/    -> Cursor
   .claude/    -> Claude Code
+  .dsh/       -> DeepSeek Harness
   .gemini/    -> Gemini CLI
   .codex/     -> Codex custom agents (Codex skills use .agents/)
   .agents/    -> Codex CLI

scripts/lib/transformers/providers.js

@@ -44,6 +44,20 @@ export const PROVIDERS = {
     displayName: 'Gemini',
     frontmatterFields: [],
   },
+  dsh: {
+    provider: 'dsh',
+    providerTags: ['dsh'],
+    configDir: '.dsh',
+    displayName: 'DeepSeek Harness',
+    // DeepSeek Harness reads the Agent Skills spec subset (`name`,
+    // `description`, `license`, `compatibility`, `metadata`) plus
+    // `user-invocable` and `disable-model-invocation`; unknown keys are
+    // silently ignored. No hook surface (hooks are in-process plugins, not
+    // on-disk manifests) and no native subagent file format, so no
+    // emitHooks / agentFormat. Global skills live at ~/.dsh/skills
+    // ($DSH_HOME/skills when set), matching the engine's home override.
+    frontmatterFields: ['user-invocable', 'license', 'compatibility', 'metadata'],
+  },
   codex: {
     provider: 'codex',
     providerTags: ['codex'],

scripts/lib/utils.js

@@ -424,6 +424,12 @@ export const PROVIDER_PLACEHOLDERS = {
     ask_instruction: 'Ask the user directly to clarify what you cannot infer.',
     command_prefix: '/'
   },
+  'dsh': {
+    model: 'DeepSeek',
+    config_file: 'AGENTS.md',
+    ask_instruction: 'STOP and call the ask_user_question tool to clarify.',
+    command_prefix: '/'
+  },
   'gemini': {
     model: 'Gemini',
     config_file: 'GEMINI.md',
@@ -524,6 +530,7 @@ export const PROVIDER_BLOCK_TAGS = new Set([
   'claude-code',
   'codex',
   'cursor',
+  'dsh',
   'gemini',
   'github',
   'grok',