fix(claude): stop pre-migration .mcp.json residue outranking a project switch

`mcpctl config claude --project X` writes user scope and never rewrites a
checkout's `.mcp.json`. The status line, however, preferred that file
unconditionally — so a legacy project-named entry an older mcpctl left behind
(`homeautomation` -> `mcpctl mcp -p homeautomation`) kept naming the old project
for good, and every switch looked like it had done nothing.

Reproduced live: with user scope on `sre`, `mcpctl statusline --directory
~/developer/michalzxc/claude/debug` printed `mcpctl:homeautomation` — a project
Claude Code also had in `disabledMcpServers` for that directory, so the line
named a server that was not even mounted.

Rank the sources by how deliberate each one is instead: a canonical `mcpctl`
pin, then user scope, then legacy residue, then the marker. A pin is a decision
and still wins; residue is not and no longer does. At every step, skip a server
Claude Code has switched off for that directory.

`config claude` now also warns when the working directory's `.mcp.json`
contradicts the switch, naming the file — the two scopes are merged rather than
chosen between, so nothing else would tell you.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019wUmrfkVQR6CKcYKxENq7k

src/cli/tests/config/claude-mcp.test.ts

@@ -5,6 +5,9 @@ import {
   projectOfEntry,
   isLegacyMcpctlEntry,
   activeProjectIn,
+  canonicalProjectIn,
+  legacyEntriesIn,
+  disabledServersFor,
 } from '../../src/config/claude-mcp.js';
 
 const bridge = (project: string): Record<string, unknown> => ({
@@ -62,6 +65,50 @@ describe('activeProjectIn', () => {
   });
 });
 
+describe('canonicalProjectIn / legacyEntriesIn', () => {
+  it('tells a deliberate pin apart from pre-migration residue', () => {
+    const config = { mcpServers: { [MCPCTL_SERVER_NAME]: bridge('sre'), homeautomation: bridge('homeautomation') } };
+    expect(canonicalProjectIn(config)).toBe('sre');
+    expect(legacyEntriesIn(config)).toEqual([{ server: 'homeautomation', project: 'homeautomation' }]);
+  });
+
+  it('reports no canonical entry when only legacy ones are present', () => {
+    const config = { mcpServers: { docmost: bridge('docmost') } };
+    expect(canonicalProjectIn(config)).toBeNull();
+    expect(legacyEntriesIn(config)).toEqual([{ server: 'docmost', project: 'docmost' }]);
+  });
+
+  it('leaves servers that are not ours out of both', () => {
+    const config = { mcpServers: { other: { command: 'echo' } } };
+    expect(canonicalProjectIn(config)).toBeNull();
+    expect(legacyEntriesIn(config)).toEqual([]);
+    expect(legacyEntriesIn(null)).toEqual([]);
+  });
+});
+
+describe('disabledServersFor', () => {
+  const doc = {
+    projects: {
+      '/repo': { disabledMcpServers: ['homeautomation'], disabledMcpjsonServers: ['mcpctl'] },
+      '/other': { disabledMcpServers: ['sre'] },
+    },
+  };
+
+  it('unions both of Claude Code\'s disable lists for that directory', () => {
+    expect([...disabledServersFor(doc, '/repo')].sort()).toEqual(['homeautomation', 'mcpctl']);
+  });
+
+  it('is scoped to the directory asked about', () => {
+    expect([...disabledServersFor(doc, '/other')]).toEqual(['sre']);
+    expect([...disabledServersFor(doc, '/unknown')]).toEqual([]);
+    expect([...disabledServersFor(null, '/repo')]).toEqual([]);
+  });
+
+  it('survives a malformed entry rather than throwing on the status line', () => {
+    expect([...disabledServersFor({ projects: { '/repo': { disabledMcpServers: 'nope' } } }, '/repo')]).toEqual([]);
+  });
+});
+
 describe('mergeMcpctlServers', () => {
   it('writes one constant entry regardless of project', () => {
     const { config } = mergeMcpctlServers(null, { project: 'my-fancy-project' });