add Flutter-rebuild project identity at the repo root

project.yaml is fresh and declares version 2.0.0-dev — a clean break
from Python clide's v1.2.0 (which remains under legacy/). It carries
module path, toolchain pins (go >=1.25, Flutter stable, Dart >=3.5),
and the Gitea repository URL. Same schema as the Makefile will read
via awk for sidecar version stamping.

README.md and LICENSE land alongside. The README pitches the rebuild
tersely and points at docs/initial-plan.md for the full story; the
Python README is preserved under legacy/README.md.

.gitignore is rewritten for the new toolchain. The previous file was
wall-to-wall Python rules; now the root ignores Flutter/Dart/Go build
output plus the usual OS/editor/secrets/.claude-local entries, and
Python-specific rules scope to legacy/** so they don't fire on any
stray caches at the repo root.

.editorconfig sets tabs for Go, two-space for Dart and everything
else, and the usual EOL + trailing-whitespace rules.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -16,6 +16,10 @@ heading, and (b) bumping `project.yaml` `version:` in the same commit.
 
 ## [Unreleased]
 
+### Changed
+
+- `.gitignore` rewritten for the new toolchain: Flutter (build output under `app/`), Dart (`.dart_tool/`), Go sidecar (`sidecar/bin/`, `sidecar/dist/`, the legacy `/clide` binary), plus the usual test/OS/editor/secret rules. Python-specific rules narrow to `legacy/**` where they still apply.
+
 ### Added
 
 - Architectural decision records carried forward from the short-lived
@@ -25,6 +29,7 @@ heading, and (b) bumping `project.yaml` `version:` in the same commit.
   [ADR 0002](docs/ADRs/0002-sidecar-language-go.md) — Sidecar language: Go.
   [ADR 0003](docs/ADRs/0003-pql-as-supporter-tool.md) — pql as supporter tool; wrap, don't duplicate; pql is a Clide subsystem when present.
   [ADR 0004](docs/ADRs/0004-ignore-file-strategy.md) — Ignore file strategy (`ignore_files:` in `.pql/config.yaml`, layered).
+- Project identity files for the Flutter rebuild at the repo root: `project.yaml` (single source of truth for version + module path, version 2.0.0-dev), a fresh `README.md`, MIT `LICENSE`, and `.editorconfig`. The Python clide's manifest and README are preserved under `legacy/`.
 - [`docs/initial-plan.md`](docs/initial-plan.md) — the north-star design document for the Flutter rebuild. Captures what we kept from Python Clide (pane model, git skills, Claude-always-visible), what we took from Obsidian (canvas and graph — no vault, no bases, no plugin inheritance), what Claudian's short experiment contributed (Go sidecar, CLI-first, pql-as-subsystem, ignore-file strategy), and the tier roadmap (Tier 0 app+sidecar handshake → Tier 5 canvas+graph).
 - Claude Code configuration under `.claude/`: project-level
   allow/deny permissions and two skills — `skill-create` (generic