fix(LifeosUpgrade): m-005 detect can never match on a case-sensitive filesystem

[m8ryx]

LifeosUpgrade.ts m-005 detects whether LIFEOS/MEMORY/ is gitignored, but tests a mixed-case pattern:

// Already-applied if any LIFEOS/MEMORY/ subpath is gitignored. The current
// policy gitignores LEARNING/, OBSERVABILITY/, STATE/, etc. selectively;
// Phase G may broaden this. For now, we detect "any LIFEOS/MEMORY/ rule" as
// applied.
return /^LifeOS\/MEMORY\//m.test(content);

The three comment lines directly above the regex say LIFEOS/MEMORY/, the migration's own name field says Phase G — LIFEOS/MEMORY/ in .gitignore, and the installed tree uses LIFEOS/. Only the pattern disagrees.

On a case-sensitive filesystem the check can therefore never match, so a correctly configured install reports m-005 as MISSING permanently — and re-reports it on every --diagnose run, with no edit to .gitignore able to satisfy it.

Reproduce

On Linux, with the standard rule present in .gitignore:

$ grep -n '^LIFEOS/MEMORY/' ~/.claude/.gitignore
265:LIFEOS/MEMORY/

$ bun LIFEOS/TOOLS/LifeosUpgrade.ts --diagnose
  ...
  ✗ MISSING  m-005  Phase G — LIFEOS/MEMORY/ in .gitignore

Measured against the same file:

lines matching ^LifeOS/MEMORY/   0
lines matching ^LIFEOS/MEMORY/   1

macOS hides this: HFS+ and APFS are case-insensitive by default, so the pattern matches there and the migration reports APPLIED.

Fix

One line — align the pattern with the directory the project actually uses:

-      return /^LifeOS\/MEMORY\//m.test(content);
+      return /^LIFEOS\/MEMORY\//m.test(content);

No behaviour change on macOS, where both forms already match. Detection-only code path; apply() is untouched.

Related casing fixes: #1273, #1259, #1175.