fix: direct-config param override crash, stale routing STA lifecycle, and sizer crash diagnostics

[Yell-walkalone]

What Changed

• fix(cli): direct-config/PDK parameters (maps_to=None, e.g. place.random_seed, route.RT.*) crashed every divergence check with AttributeError: 'NoneType' object has no attribute 'items' — both ecc run --set and project-level ecc param set + run, before any EDA step started. _backend_leaf_keys now returns an empty tuple for them (they are applied through their explicit config_target), and a diverging direct-config override reports its canonical parameter name instead of an invented backend leaf key.
• fix(ecc): timing-driven routing (route.RT.-enable_timing=1) crashed the routing step with AttributeError: 'ECCToolsModule' object has no attribute 'release_sta'. The STA pre-init block (and save_data's unreachable report_timing block) referenced an ecc-tools lifecycle removed on 2026-07-29 (1a4440525). Removed rather than ported: iRT's RTInterface builds its own timing engine from the shared db config (lib paths/SDC set by load_data), verified against the pinned submodule source. The unused is_rt_timing_enable wrapper is dropped with it.
• feat(sizer): Timing-opt failures now distinguish a fatal signal (signal=SIGABRT(6)) from a plain exit (exit_code=N) and surface the first native fatal banner from the step log, keeping tool crashes, external kills, and timeouts separable in wrapper evidence.

Before/after for the CLI crash (fresh manifest project):

# before: rc=1, no EDA step starts
ecc run --set place.random_seed=3001 --from Synth --to Synth
AttributeError: 'NoneType' object has no attribute 'items'   # effective_config.py:415

# after: rc=0, run succeeds; DreamPlace receives random_seed=3001

Scope

• CLI - command behavior, Typer command surface, output formats, or workspace commands.
• Flow/runtime - workspace lifecycle, EngineFlow, step execution, logs, metrics, or artifacts.
• EDA integration - Yosys, ECC-Tools, DreamPlace, PDKs, or native/runtime wrappers.
• Build/package - Nix, PyInstaller, wheels, uv.lock, or release artifacts.
• CI/release - GitHub Actions, version checks, changelog, or release automation.
• Tests/docs only

Runtime And Packaging Impact

• No runtime or packaging impact
• CLI output or machine-readable contract changed
• Workspace layout, flow state, or artifact paths changed
• Native toolchain or wrapper behavior changed
• ecc-tools or ecc-dreamplace dependency changed
• PyInstaller, Nix, or release artifact changed

Notes:

• Sizer wrapper failure log line changes from exit code=%d to termination reason + fatal_log_line; it is log text only, no machine-readable contract. The config_layer_diverged warning can now include canonical parameter names for direct-config keys (previously this path crashed instead of warning).
• Routing behavior with default -enable_timing=0 is unchanged; the enabled path goes from guaranteed crash to running through iRT's self-contained timing engine.
• No submodule pointer change: the fix adapts ECC to the already-pinned ecc-tools commit.

Validation

List the commands you ran. Mark checks that are not applicable as N/A.

• uv run pytest test/
• uv run ruff check chipcompiler test
• uv run ruff format --check chipcompiler test
• PyInstaller smoke: ecc --help, ecc --version, ecc version --json (via local release-format bundle build, plus tarball extract smoke)
• Nix smoke: nix run .#cli -- --help
• Manual flow smoke:
• Other:

Exact commands:

uv run pytest test/cli/commands/test_effective_config.py test/cli/commands/test_config_layers.py \
  test/cli/commands/test_manifest_run.py test/cli/params/
uv run pytest test/yosys_lec test/tools/ecc_sizer test/tools/ecc test/runtime/test_signoff_export.py
uv run pytest test/ -m "not integration"        # 2551 passed, 1 pre-existing failure (see below)
uv run ruff check chipcompiler test
uv run ruff format --check chipcompiler test

Manual flow smoke (real gcd design, rtl2gds preset, repo venv):

• ecc run --set place.random_seed=3001 --from Synth --to place → success; config/dreamplace_ecc.json and the DreamPlace parameter dump contain random_seed: 3001.
• ecc run --set route.RT.-enable_timing=1 --from Synth --to route → success after the STA fix; router runs in timing mode (enable_timing honored, timing table rendered), route outputs produced.
• ecc param set place.random_seed 3001 + ecc run on existing workspace → success with the by-design params_ignored_on_existing_run warning; on a fresh workspace the value reaches the generated DreamPlace config.
• ecc param set route.RT.-enable_timing 1 + ecc run on existing workspace → success; fresh workspace generates "-enable_timing": "1" in config/route_ecc.json and completes through route.

Skipped checks and reason:

• uv run pytest test/ (integration included): run locally as -m "not integration"; the integration suite runs in CI with a fresh PDK/yosys/Sizer setup. One local non-integration failure is pre-existing and environment-caused: test_pyplacedb_macro_writeback.py::test_macro_writeback_commits_only_frozen_candidates fails against this machine's stale locally-built ecc_py (older than the submodule's macro-writeback-orientation fix) and fails identically on unmodified main.
• Nix smoke: no nix/ or packaging input changed.

Checklist

• I kept the change scoped to ECC.
• I updated docs or user-facing CLI text where behavior changed.
• I included lockfile or version metadata updates when dependencies changed.
• I documented any submodule updates and why they are needed.
• I did not include local caches, virtual environments, or generated build outputs.
• I explained skipped validation and remaining risk.