ci(language-policy): DRY local Java/Kotlin check via estate reusable (#117)

## Why

PR #105 added the android/** carve-out via **two** mechanisms:

- (a) Prune `android/` from a local `find` step in
`.github/workflows/language-policy.yml`
- (b) Add `.hypatia-baseline.json` with `file_pattern: "android/**"`

The estate-wide reusable at
`hyperpolymath/standards/.github/workflows/governance-reusable.yml`
(called from this repo's `governance.yml`) **already** reads
`.hypatia-baseline.json` and exempts matched paths in its own
`language-policy` job (see `governance-reusable.yml:91-285`).

**(b) alone is sufficient.** (a) is a duplicate that uses the brittle
`find` mechanism the reusable explicitly warns against — `git ls-files`
respects `.gitignore` correctly.

## What this PR does

Removes the local `Check for Java/Kotlin files` step. The neurophone
`.hypatia-baseline.json` carve-out continues to handle the android/**
exemption via the estate-wide reusable.

## Net behaviour change

**Zero.** The local check duplicated the estate check. Both gate on
Java/Kotlin files; both exempt android/** via different mechanisms.
Removing the local check means there's one mechanism instead of two, and
the remaining mechanism is the auditable baseline file.

## Properties preserved

- Kotlin (`.kt`, `.kts`) is still fully banned — by the estate-wide
reusable's `enforce "Java/Kotlin files"` block.
- Non-Android Java (e.g. a stray `Foo.java` at repo root) is still
blocked — same path.
- The `android/**` carve-out is still respected via
`.hypatia-baseline.json`.

## Stale-entry cleanup at end of migration

When the Gossamer migration completes and `android/` is removed, the
baseline entry will become stale. The reusable's `Detect stale baseline
entries` job (`governance-reusable.yml:127+`) will warn. The entry can
be removed in the same PR that deletes `android/` (i.e. sub-PR #9 of the
migration sequence in RFC PR #97).

## Supersedes

- `hyperpolymath/standards#341` (closed) — estate-wide grep change was
redundant given the baseline mechanism already exists.
- `#107` (closed) — same intent as this PR but
pre-#105; rebase would have been a different change.

## Test plan

- [x] Workflow YAML is well-formed (visually verified).
- [ ] CI passes — local language-policy.yml runs without the Java/Kotlin
step; estate-wide reusable runs and exempts android/** via baseline.
- [ ] Negative test: a hypothetical `Foo.java` at repo root would still
trigger the estate-wide `Language / package anti-pattern policy` job
(verified by inspection of `governance-reusable.yml:345` + `enforce()`
at line 310 + `is_exempt()` at line 292).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: hyperpolymath

.github/workflows/language-policy.yml

@@ -84,24 +84,28 @@ jobs:
           fi
           echo "✓ No npm runtime dependencies found"
 
-      - name: Check for Java/Kotlin files
-        run: |
-          # Carve-out: the android/ subtree is owner-authored Kotlin/Gradle
-          # code currently being migrated to Gossamer (RFC PR #97). It is
-          # not vendored upstream — it is intentional work-in-flight. Once
-          # the Gossamer migration lands and android/ is removed, this
-          # exclusion should be removed too. Mirrors the .hypatia-ignore /
-          # .hypatia-baseline.json carve-out consumed by the standards
-          # governance-reusable workflow.
-          VIOLATIONS=$(find . \
-            \( -path './android' -o -path './android/*' -o -path './.git/*' \) -prune -o \
-            \( -name "*.java" -o -name "*.kt" -o -name "*.kts" \) -type f -print)
-          if [ -n "$VIOLATIONS" ]; then
-            echo "::error::Java/Kotlin files found. Use Rust/Tauri/Dioxus instead."
-            echo "$VIOLATIONS"
-            exit 1
-          fi
-          echo "✓ No Java/Kotlin files found (android/ exempt — Gossamer migration in flight, RFC PR #97)"
+      # Java/Kotlin check is delegated to the estate-wide standards
+      # `governance-reusable.yml language-policy` job (called from this
+      # repo's governance.yml). That reusable already:
+      #   - reads `.hypatia-baseline.json` and honours `file_pattern`
+      #     entries (governance-reusable.yml:91-285);
+      #   - uses `git ls-files` (which respects .gitignore correctly,
+      #     unlike `find` — see governance-reusable.yml:331-337);
+      #   - emits an explicit "exempt" line per skipped match for audit
+      #     trail.
+      #
+      # The neurophone-local `.hypatia-baseline.json` already declares
+      # the android/** carve-out for the Gossamer migration (PR #97).
+      # That single source of truth is enough; the previous local
+      # duplicate find-based check both (a) duplicated the policy and
+      # (b) used the brittle `find` mechanism that the reusable comment
+      # explicitly warned against.
+      #
+      # When the Gossamer migration completes and android/ is removed,
+      # the baseline entry will become stale — the reusable's
+      # `Detect stale baseline entries` job (governance-reusable.yml:127
+      # onward) will warn, and the entry can be removed in the same PR
+      # that deletes android/.
 
       - name: Check for Swift files
         run: |