retire Go sidecar; adopt Dart core (ADR 0005)

ADR 0005 supersedes ADR 0002. The "sidecar vs app" split was
load-bearing on Go-vs-Dart being a meaningful boundary. Going
all-Dart collapses that — the daemon becomes clide --daemon mode
of the same AOT binary the CLI lives in, both sharing lib/ with
the Flutter app. The one native gap (Dart's multi-threaded VM
can't safely fork+exec) is filled by a small C supporter tool —
ptyc, Project Terminal Controller, peer of pql — rather than
introducing a second core language.

ADR 0006 defines the CLI/event surface on top of that Dart core:
subsystem list (pane/tab/editor/panel/tree/git/pql/canvas/graph/
theme/settings/project), command shape, versioned JSON event
schema, pql-parity exit codes, and command-event duality as the
operational form of user/Claude parity.

Deleted: sidecar/cmd, sidecar/go.mod, every sidecar/internal
package. Rewritten: Makefile (dart compile exe, flutter
analyze/format/test, build-linux/build-macos, ptyc-build),
ci/*.sh, .githooks/pre-push (no more GOBIN PATH dance),
.gitignore (Flutter/Dart at repo root, ptyc section),
project.yaml (drop module: and go_version:), CLAUDE.md
(guardrails, dependencies, commands refreshed).

Co-Authored-By: Claude <noreply@anthropic.com>

ci/lint.sh

@@ -7,6 +7,6 @@ set -euo pipefail
 
 cd "$(dirname "$0")/.."
 
-make lint
-make app-analyze
+make analyze
+make format
 make security

ci/security.sh

@@ -3,8 +3,9 @@
 # local dev and CI run the same commands.
 #
 # See ~/.claude/projects/-var-mnt-data-projects-clide/memory/ for the
-# standing requirements: Go deps must be version-locked and CVE-checked;
-# Dart deps prefer zero, with what remains pinned and audited.
+# standing requirement: Dart deps prefer zero; what remains is pinned
+# and advisory-audited before bumping. Native supporter tools (ptyc, any
+# future peer) are reviewed by reading them — they have no dep graph.
 set -euo pipefail
 
 cd "$(dirname "$0")/.."

ci/test.sh

@@ -5,5 +5,4 @@ set -euo pipefail
 cd "$(dirname "$0")/.."
 
 make test
-make test-race
-make app-test
+make test-integration