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/tools.ts

@@ -700,6 +700,64 @@ export const TOOLS_BY_NAME: Record<string, ToolDef<unknown>> = Object.fromEntrie
   ALL_TOOLS.map((t) => [t.name, t])
 );
 
+// v1.13.15-tools: tiered tool loading. BOOCODE_TOOLS env var (`core` |
+// `standard` | `all`) filters the agent's tool whitelist before LLM dispatch.
+// Daily-driver token win on qwen3.6-35b-a3b — the 35B-A3B MoE benefits from
+// any prompt-cache stability win (fewer tools = shorter, more stable tool
+// schemas in the system prompt). Pattern lift from eyaltoledano/claude-task-
+// master (MIT + Commons Clause — pattern only, no code lift).
+//
+// The env var is a CEILING. It only narrows; never expands an agent's
+// declared whitelist. Default behavior (var unset) is unchanged: all tools.
+export const CORE_TOOL_NAMES = [
+  'view_file',
+  'list_dir',
+  'grep',
+  'find_files',
+] as const;
+
+export const STANDARD_TOOL_NAMES = [
+  ...CORE_TOOL_NAMES,
+  'web_search',
+  'web_fetch',
+  'git_status',
+  'get_codebase_overview',
+  'get_file_analysis',
+  'get_symbol_info',
+  'search_symbols',
+  'get_dependencies',
+  'watch_changes',
+  'get_semantic_neighborhoods',
+  'get_framework_analysis',
+] as const;
+
+// Module-load validation: every name in CORE / STANDARD must exist in
+// TOOLS_BY_NAME. Catches typos and stale tier definitions before they reach
+// production; server boot fails loudly rather than silently filtering valid
+// tools out of agent whitelists.
+for (const name of CORE_TOOL_NAMES) {
+  if (!TOOLS_BY_NAME[name]) {
+    throw new Error(`CORE_TOOL_NAMES references unknown tool: '${name}'`);
+  }
+}
+for (const name of STANDARD_TOOL_NAMES) {
+  if (!TOOLS_BY_NAME[name]) {
+    throw new Error(`STANDARD_TOOL_NAMES references unknown tool: '${name}'`);
+  }
+}
+
+export function resolveToolTier(tier: string | undefined): readonly string[] {
+  switch ((tier ?? 'all').toLowerCase()) {
+    case 'core':
+      return CORE_TOOL_NAMES;
+    case 'standard':
+      return STANDARD_TOOL_NAMES;
+    case 'all':
+    default:
+      return ALL_TOOLS.map((t) => t.name);
+  }
+}
+
 export function toolJsonSchemas(): ToolJsonSchema[] {
   return ALL_TOOLS.map((t) => t.jsonSchema);
 }