v1.13.15-tools: tiered tool loading via BOOCODE_TOOLS env var

Pattern lift from eyaltoledano/claude-task-master (MIT + Commons Clause
— pattern only, no code lift). Adds BOOCODE_TOOLS env var with three
tiers:

- core (4 tools): view_file, list_dir, grep, find_files. ~2k token
  schema cost.
- standard (15 tools): core + web_search, web_fetch, git_status, all
  8 codecontext_* tools. ~10k token schema cost.
- all (default; current behavior): every tool in ALL_TOOLS (20). ~21k
  token schema cost.

The env var is a CEILING — narrows agent whitelists, never expands.
Default behavior unchanged when var is unset. resolveToolTier is
case-insensitive and falls back to 'all' on unknown values.

CORE_TOOL_NAMES + STANDARD_TOOL_NAMES validated at module load against
TOOLS_BY_NAME via two top-level for-loops that throw on the first
missing name. Module fails to import if a tier references a tool that
doesn't exist in the registry — catches typos and stale tier
definitions at boot rather than silently filtering valid tools out of
agent whitelists.

Wiring: agents.ts parseAgentBlock now reads BOOCODE_TOOLS from
process.env per parse, intersects with the agent's declared frontmatter
tools (or DEFAULT_TOOLS when frontmatter omits the field). Per-parse
read is fine — agents are re-parsed on the existing 60s cache TTL.

Tests: tools.test.ts grows from 1 to 10 tests. Covers resolveToolTier
across tiers/case/unknown values + the CORE-subset-of-STANDARD invariant
+ TOOLS_BY_NAME existence for both tier sets. 204/204 pass (was 195;
+9 new).

Deviation from the brief: the codecontext tools in the actual registry
have NO codecontext_* prefix (the brief's STANDARD list assumed it).
Used the actual names (get_codebase_overview, search_symbols, etc.).
Module-load validation would have failed boot with the prefixed names.

Smoke: with BOOCODE_TOOLS unset, agents return their full 12-tool
whitelists. With BOOCODE_TOOLS=core in .env + container restart, the
same agents narrow to 4 tools (find_files, grep, list_dir, view_file)
— intersection of declared whitelist ∩ core tier. Reverted after
confirmation.

CLAUDE.md updated with BOOCODE_TOOLS in the Environment section's
Optional list. .env.example gained a commented BOOCODE_TOOLS=all line
with the per-tier token-cost table.

~110 LoC across 5 files (4 modified + 1 test expansion). Under the
brief's ~30 LoC estimate for code; the test suite expansion drove
most of the growth.

apps/server/src/services/__tests__/tools.test.ts

@@ -1,5 +1,11 @@
 import { describe, it, expect } from 'vitest';
-import { ALL_TOOLS } from '../tools.js';
+import {
+  ALL_TOOLS,
+  CORE_TOOL_NAMES,
+  STANDARD_TOOL_NAMES,
+  TOOLS_BY_NAME,
+  resolveToolTier,
+} from '../tools.js';
 
 describe('ALL_TOOLS registry', () => {
   // v1.13.3: tools must be alpha-sorted at module load. llama.cpp's prompt
@@ -12,3 +18,59 @@ describe('ALL_TOOLS registry', () => {
     expect(names).toEqual([...names].sort((a, b) => a.localeCompare(b)));
   });
 });
+
+describe('resolveToolTier (v1.13.15-tools)', () => {
+  it('returns CORE tools for tier=core', () => {
+    expect(resolveToolTier('core')).toEqual(CORE_TOOL_NAMES);
+  });
+
+  it('returns STANDARD tools for tier=standard', () => {
+    const result = resolveToolTier('standard');
+    expect(result.length).toBe(STANDARD_TOOL_NAMES.length);
+    expect(result.length).toBeGreaterThan(CORE_TOOL_NAMES.length);
+    // STANDARD is a strict superset of CORE.
+    expect(result).toEqual(expect.arrayContaining([...CORE_TOOL_NAMES]));
+  });
+
+  it('returns ALL tool names for tier=all', () => {
+    expect(resolveToolTier('all').length).toBe(ALL_TOOLS.length);
+  });
+
+  it('defaults to all when env var is undefined', () => {
+    expect(resolveToolTier(undefined).length).toBe(ALL_TOOLS.length);
+  });
+
+  it('is case-insensitive', () => {
+    expect(resolveToolTier('CORE')).toEqual(CORE_TOOL_NAMES);
+    expect(resolveToolTier('Standard').length).toBe(STANDARD_TOOL_NAMES.length);
+  });
+
+  it('falls back to all for unknown tier strings', () => {
+    expect(resolveToolTier('bogus').length).toBe(ALL_TOOLS.length);
+  });
+});
+
+describe('CORE_TOOL_NAMES + STANDARD_TOOL_NAMES validation', () => {
+  // The module-load validation in tools.ts throws if a tier references a
+  // tool that doesn't exist in TOOLS_BY_NAME. These tests double-check that
+  // invariant from the consumer side so a future tier-list edit can't smuggle
+  // in a typo without a test failure.
+  it('every CORE name exists in TOOLS_BY_NAME', () => {
+    for (const name of CORE_TOOL_NAMES) {
+      expect(TOOLS_BY_NAME[name], `CORE references unknown tool '${name}'`).toBeDefined();
+    }
+  });
+
+  it('every STANDARD name exists in TOOLS_BY_NAME', () => {
+    for (const name of STANDARD_TOOL_NAMES) {
+      expect(TOOLS_BY_NAME[name], `STANDARD references unknown tool '${name}'`).toBeDefined();
+    }
+  });
+
+  it('CORE is a subset of STANDARD', () => {
+    const standardSet = new Set<string>(STANDARD_TOOL_NAMES);
+    for (const name of CORE_TOOL_NAMES) {
+      expect(standardSet.has(name), `'${name}' is in CORE but not STANDARD`).toBe(true);
+    }
+  });
+});