refactor(architecture): relocate tracedecay root package

.github/workflows/ci.yml

@@ -221,8 +221,17 @@ jobs:
           shared-key: ci-test-full-${{ runner.os }}
           cache-on-failure: true
 
+      # Every `crates/tracedecay` integration target declares
+      # `required-features = ["test-helpers"]`, because the fixture surface it
+      # gates is used by `tests/common/mod.rs`. Those targets are selected here
+      # today only as a side effect of dev-dependency feature unification
+      # (`tracedecay-cli` dev-depends on `tracedecay` with that feature), which
+      # is not a property this lane should depend on: it would evaporate the
+      # moment that dev-dependency changes, and nextest would then silently
+      # select zero of them and report green having run nothing. Asking for the
+      # feature explicitly makes the selection independent of that accident.
       - name: Run tests
-        run: cargo nextest run --workspace --profile ci --locked
+        run: cargo nextest run --workspace --profile ci --locked --features tracedecay/test-helpers
 
       # Compile-only gate for the features this lane does not enable. Both are
       # otherwise built for the first time at release (`--all-features`), so

.github/workflows/plugin-validation.yml

@@ -13,14 +13,14 @@ on:
       - "plugin/**"
       - "plugin/cursor-native-extension/**"
       - "tests/fixtures/cursor-schemas/**"
-      - "tests/agent_suite/*plugin*"
-      - "tests/agent_suite/*skill*"
+      - "crates/tracedecay/tests/agent_suite/*plugin*"
+      - "crates/tracedecay/tests/agent_suite/*skill*"
       - "scripts/mcp-conformance-smoke.sh"
       - "scripts/check-dashboard-bundle.py"
-      - "src/serve.rs"
+      - "crates/tracedecay/src/serve.rs"
       - "crates/tracedecay-cli/**"
-      - "src/lib.rs"
-      - "src/mcp/**"
+      - "crates/tracedecay/src/lib.rs"
+      - "crates/tracedecay/src/mcp/**"
       - "Cargo.toml"
       - "Cargo.lock"
       - ".github/workflows/plugin-validation.yml"

.github/workflows/sdk-conformance.yml

@@ -21,7 +21,7 @@ on:
       - "scripts/plan-release-recovery.py"
       - "scripts/test-plan-release-recovery.py"
       - "tests/release_safety_test.sh"
-      - "src/application_surface.rs"
+      - "crates/tracedecay/src/application_surface.rs"
   push:
     branches: [master]
 

AGENTS.md

@@ -13,18 +13,26 @@ compiles.
 
 ## Layout
 
-- `src/` — main `tracedecay` crate (daemon, MCP tools, global DB, sessions,
-  code index, application services).
-- `crates/` — workspace member crates (`tracedecay-api`, `-application`,
-  `-domain`, `-store`, `-hooks`, `-policy`, `-tool-catalog`, rusqlite
-  parity/runtime crates).
+- The repository root is a **virtual workspace** — it has no package of its
+  own. Every crate lives under `crates/`.
+- `crates/tracedecay/` — the composition-root library (daemon, MCP tools,
+  global DB, sessions, code index, application services). Its integration
+  suites are `crates/tracedecay/tests/`, and the ones that use the fixture
+  surface in `tests/common/` declare `required-features = ["test-helpers"]`.
+- `crates/tracedecay-cli/` — the shipped `tracedecay` binary. Build it with
+  `cargo build -p tracedecay-cli --bin tracedecay`, never `-p tracedecay`.
+- `crates/` — the remaining workspace member crates (`tracedecay-api`,
+  `-application`, `-domain`, `-store`, `-hooks`, `-policy`, `-tool-catalog`,
+  rusqlite parity/runtime crates).
 - `dashboard/` — the single embedded dashboard (React + rsbuild + vitest).
   `dashboard/src/contracts/` is generated from Rust schemas via schemars —
   never hand-edit it; regenerate with the `contracts:generate` script and
   verify with `contracts:check`.
 - `plugin/` — host bundles (Claude, Codex, Cursor, Kimi, opencode).
-- `tests/` — integration test suites; `benches/` — criterion benches;
-  `benchmark_data/` — benchmark fixtures, harnesses, and provenance;
+- `tests/` — shared fixtures, distribution suites, and shell/Python gates that
+  no single crate owns; crate-level integration suites and criterion benches
+  live under that crate's own `tests/` and `benches/`.
+- `benchmark_data/` — benchmark fixtures, harnesses, and provenance;
   `evals/` — memory, hermetic, and agent-adoption evals; `docs/` — plans and guides.
 - `scripts/` — CI/dev gates (commit-msg check, bundle checks, release drift).