feat(dialect): add Zed adapter compiling skills to .agents/skills (fixes #15)

[nilay1221]

Summary

Add Zed as Cinch's 10th supported harness. cinch init --harness zed and cinch preview <item> --target zed now compile skills, agents, and commands into Zed's native Agent Skills layout at .agents/skills/<name>/SKILL.md.

Implements #15.

Scope decision: vendor accuracy over the issue's proposed .zed/prompts/

Issue #15 proposed .zed/prompts/<name>.md. Current Zed documentation does not define a .zed/prompts/ format. Per CONTRIBUTING.md ("Vendor Accuracy: every target path and dialect emitted is backed by vendor documentation"), this PR targets the documented layout instead:

• Global: ~/.agents/skills/<name>/SKILL.md
• Project-local: <worktree>/.agents/skills/<name>/SKILL.md (flat; nested folders are not discovered)
• Frontmatter: name, description, optional disable-model-invocation only

Recorded in tests/conformance/zed/SOURCE.md against https://zed.dev/docs/ai/skills.

Out of scope, as agreed: .zed/prompts/, MCP/context servers, AGENTS.md/.rules, hook translation, and the pre-existing wire.py support-copy quirk (documented below, not fixed).

What changed

File	Change
src/cinch/adapters.py	New ZedAdapter (renders .agents/skills/<name>/SKILL.md, emits no paths; commands get disable-model-invocation: true) registered in ADAPTERS
src/cinch/catalog.py	"zed" appended to HARNESS_ORDER; HARNESSES["zed"] spec (binaries/home markers/project markers/skill source/project dirs)
tests/conformance/zed/SOURCE.md	Vendor conformance fixture
tests/test_translation.py	TestZedAdapter unit tests + single-target and cursor,zed shared-path integration tests
tests/test_cinch.py	Harness-id list + Zed title assertion; non-interactive init --harness zed and preview --target zed coverage
tests/test_conformance.py	Docstring count 9 → 10 (parametrized suite now covers zed)
README.md	Badge 9 → 10; matrix row; performance-table label; new Zed docs subsection (paths, / + @skill invocation, cmd-alt-l/ctrl-alt-l, trusted worktree, link)
CHANGELOG.md	Unreleased → Added entry
pyproject.toml	Description/keywords mention Zed
examples/README.md	Notes .agents/skills/ is also read by Zed
benchmark/run.py	Docstrings and results header made dynamic (10 adapters) instead of hard-coded 9

Shared path behaviour

Zed shares .agents/skills/ with Cursor and Codex. A --harness cursor,zed run writes the file once (as Cursor's rendering, which includes paths) and reports Zed as shared with shared_with: "cursor"; the extra paths key is ignored by Zed. Wire --harness zed alone for Zed's minimal frontmatter. This ordering is covered by test_cursor_and_zed_share_agents_path.

Known behaviour (documented, not fixed)

wire.py::_apply_file copies a skill's support directory before writing the main file. When support_dest is the parent of the main relpath (Claude/Cursor/Codex/Zed multi-file skills), the copied SKILL.md makes the destination pre-exist, so the outcome can be exists rather than written. Pre-existing, unaffected by this change, left out of scope.

Verification

uv run ruff check src tests        # all checks passed
uv run ruff format --check src tests  # 33 files already formatted
uv run pytest                      # 122 passed

Also verified manually: cinch harnesses lists Zed; cinch inventory --harness zed runs and lists Zed; benchmark/run.py reports Adapters Tested (10) and Translation Latency (10 dialects).

[00200200]

Excellent work @nilay1221! Comprehensive adapter implementation, thorough conformance tests, and accurate vendor documentation. Thank you for contributing! 🚀