feat(cli): add transitrix bin alias, deprecate cervin (P1)

[vkgeorgia]

Summary

First phase of the Cervin → Transitrix gradual CLI rename (CLAUDE.md §Cervin naming, P1). No breaking change — cervin keeps working.

Closes the acceptance criteria of strategy hub issue #188.

Changes

• package.json — bin gains a transitrix entry pointing at the same dist/cli.js as cervin; added an npm run transitrix script alongside npm run cervin. The cervin bin is kept (no removal this phase).
• src/cli.ts — usage/--help text now recommends transitrix; a one-line deprecation notice is printed to stderr when the tool is launched under the legacy cervin name (so it never pollutes --json output).
• src/cli-parse.ts — new pure invokedAsCervin(argv1) helper + CERVIN_DEPRECATION_NOTICE constant. Detection is best-effort from argv[1]: fires on POSIX symlink shims (.../bin/cervin), degrades silently on Windows .cmd shims (which invoke node with the resolved cli.js path).
• tests/cli-parse.test.ts — unit tests for the detector and notice (POSIX/Windows paths, case-insensitivity, negative cases).
• CHANGELOG.md — Added/Deprecated entries: "cervin CLI is deprecated, use transitrix".

Verification

• npm run compile (tsc --noEmit) — clean.
• npx vitest run — 242 tests green.
• Manual: --help shows transitrix … usage; deprecation notice fires for an argv[1] basename of cervin.

Notes

Internal error-message prefixes (cervin: …) are intentionally left untouched — they're part of the later opportunistic internal rename, not the user-facing P1 surface. Next phase: P2 (extension settings, #189).

🤖 Generated with Claude Code

[github-actions]

📊 Metrics Regression Report

✅ All metrics within tolerance

Summary

• Diagrams tested: 8
• Successful: 8
• Failed: 0
• Violations: 0

Details

ai-expense-approval.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	1	1	0.00	✓
bends	10	10	0.00	✓
edgeLength	1992.6666666666665	1992.6666666666665	0.00 (0.0%)	✓
waypointDensity	3	3	0.00 (0.0%)	✓
spineDeviation	0	0	0.00	✓
emptyArea	0.5869700748129676	0.5869700748129676	0.00	✓
portViolations	0	0	0.00	✓

feature-release.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	1	1	0.00	✓
bends	13	13	0.00	✓
edgeLength	3460	3460	0.00 (0.0%)	✓
waypointDensity	3	3	0.00 (0.0%)	✓
spineDeviation	0	0	0.00	✓
emptyArea	0.5500909090909091	0.5500909090909091	0.00	✓
portViolations	0	0	0.00	✓

large-cyclic-workflow.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	1	1	0.00	✓
bends	29	29	0.00	✓
edgeLength	7042.666666666667	7042.666666666667	0.00 (0.0%)	✓
waypointDensity	3.16	3.16	0.00 (0.0%)	✓
spineDeviation	82	82	0.00	✓
emptyArea	0.7965322633390317	0.7965322633390317	0.00	✓
portViolations	2	2	0.00	✓

order-fulfillment.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	0	0	0.00	✓
bends	2	2	0.00	✓
edgeLength	704	704	0.00 (0.0%)	✓
waypointDensity	2.3333333333333335	2.3333333333333335	0.00 (0.0%)	✓
spineDeviation	0	0	0.00	✓
emptyArea	0.5462701149425288	0.5462701149425288	0.00	✓
portViolations	0	0	0.00	✓

simple-approval.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	0	0	0.00	✓
bends	8	8	0.00	✓
edgeLength	1542	1542	0.00 (0.0%)	✓
waypointDensity	3.142857142857143	3.142857142857143	0.00 (0.0%)	✓
spineDeviation	41	41	0.00	✓
emptyArea	0.7764882411250177	0.7764882411250177	0.00	✓
portViolations	0	0	0.00	✓

simple-linear.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	0	0	0.00	✓
bends	0	0	0.00	✓
edgeLength	440	440	0.00 (0.0%)	✓
waypointDensity	2	2	0.00 (0.0%)	✓
spineDeviation	0	0	0.00	✓
emptyArea	0.5258771929824562	0.5258771929824562	0.00	✓
portViolations	0	0	0.00	✓

small-dense-approval.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	0	0	0.00	✓
bends	14	14	0.00	✓
edgeLength	2158	2158	0.00 (0.0%)	✓
waypointDensity	3.272727272727273	3.272727272727273	0.00 (0.0%)	✓
spineDeviation	41	41	0.00	✓
emptyArea	0.8091206777597997	0.8091206777597997	0.00	✓
portViolations	0	0	0.00	✓

xlarge-stress-test.bpmn.transitrix.yaml

Metric	Baseline	Current	Delta	Status
crossings	1	1	0.00	✓
bends	90	90	0.00	✓
edgeLength	11756.583333333332	11756.583333333332	0.00 (0.0%)	✓
waypointDensity	3.6666666666666665	3.6666666666666665	0.00 (0.0%)	✓
spineDeviation	148	148	0.00	✓
emptyArea	0.8282701728700941	0.8282701728700941	0.00	✓
portViolations	0	0	0.00	✓