feat(skills): implement M10 advanced skills (#96)

* feat(skills): implement M10 advanced skills (#74)

Add embedding-based skill matcher with cosine similarity for dynamic
per-query skill selection, replacing static inject-all behavior.
Implement filesystem watcher for hot-reload of SKILL.md files with
500ms debounce. Add skill priority system where earlier config paths
take precedence. Track skill usage in SQLite with /skills command.
Include three new bundled skills: git, docker, api-request.

Closes #75, closes #76, closes #77

* chore: bump version to 0.5.0 (#96)

Release M10 Advanced Skills as v0.5.0. Update CHANGELOG, README
with embedding-based skill matching, hot-reload, usage tracking.

Author: bug-ops

CHANGELOG.md

@@ -6,6 +6,31 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 
+## [0.5.0] - 2026-02-08
+
+### Added
+- Embedding-based skill matcher: `SkillMatcher` with cosine similarity selects top-K relevant skills per query instead of injecting all skills into the system prompt (Issue #75)
+- `max_active_skills` config field (default: 5) with `ZEPH_SKILLS_MAX_ACTIVE` env var override
+- Skill hot-reload: filesystem watcher via `notify-debouncer-mini` detects SKILL.md changes and re-embeds without restart (Issue #76)
+- Skill priority: earlier paths in `skills.paths` take precedence when skills share the same name (Issue #76)
+- `SkillRegistry::reload()` and `SkillRegistry::into_skills()` methods
+- SQLite `skill_usage` table tracking per-skill invocation counts and last-used timestamps (Issue #77)
+- `/skills` command displaying available skills with usage statistics
+- Three new bundled skills: `git`, `docker`, `api-request` (Issue #77)
+- 17 new unit tests for matcher, registry priority, reload, and usage tracking
+
+### Changed
+- `Agent::new()` signature: accepts `Vec<Skill>`, `Option<SkillMatcher>`, `max_active_skills` instead of pre-formatted skills prompt string
+- `format_skills_prompt` now generic over `Borrow<Skill>` to accept both `&[Skill]` and `&[&Skill]`
+- `Skill` struct derives `Clone`
+- `Agent` generic constraint: `P: LlmProvider + Clone + 'static` (required for embed_fn closures)
+- System prompt rebuilt dynamically per user query with only matched skills
+
+### Dependencies
+- Added `notify` 8.0, `notify-debouncer-mini` 0.6
+- `zeph-core` now depends on `zeph-skills`
+- `zeph-skills` now depends on `tokio` (sync, rt) and `notify`
+
 ## [0.4.3] - 2026-02-08
 
 ### Fixed

Cargo.lock

@@ -5,7 +5,7 @@ resolver = "3"
 [workspace.package]
 edition = "2024"
 rust-version = "1.88"
-version = "0.4.3"
+version = "0.5.0"
 authors = ["bug-ops"]
 license = "MIT"
 repository = "https://github.com/bug-ops/zeph"
@@ -15,6 +15,8 @@ anyhow = "1.0"
 criterion = "0.8"
 eventsource-stream = "0.2"
 futures-core = "0.3"
+notify = "8"
+notify-debouncer-mini = "0.7"
 ollama-rs = { version = "0.3", default-features = false, features = ["rustls", "stream"] }
 pulldown-cmark = "0.13"
 qdrant-client = { version = "1.16", default-features = false }
@@ -33,12 +35,12 @@ toml = "0.9"
 tracing = "0.1"
 tracing-subscriber = "0.3"
 uuid = "1.20"
-zeph-channels = { path = "crates/zeph-channels", version = "0.4.3" }
-zeph-core = { path = "crates/zeph-core", version = "0.4.3" }
-zeph-llm = { path = "crates/zeph-llm", version = "0.4.3" }
-zeph-memory = { path = "crates/zeph-memory", version = "0.4.3" }
-zeph-skills = { path = "crates/zeph-skills", version = "0.4.3" }
-zeph-tools = { path = "crates/zeph-tools", version = "0.4.3" }
+zeph-channels = { path = "crates/zeph-channels", version = "0.5.0" }
+zeph-core = { path = "crates/zeph-core", version = "0.5.0" }
+zeph-llm = { path = "crates/zeph-llm", version = "0.5.0" }
+zeph-memory = { path = "crates/zeph-memory", version = "0.5.0" }
+zeph-skills = { path = "crates/zeph-skills", version = "0.5.0" }
+zeph-tools = { path = "crates/zeph-tools", version = "0.5.0" }
 
 [workspace.lints.clippy]
 all = "warn"