mcp.c: add missing parameter descriptions for name_pattern, qn_pattern, sort_by, function_name

Previous behavior: name_pattern and qn_pattern had no JSON schema description
in either classic or streamlined tool mode — AI clients saw only
{"type":"string"} with no hint that the field accepts regex or auto-converts
glob wildcards. sort_by in streamlined mode had the enum but no description
of what each value means. function_name in trace_call_path said only
"Function name to trace" with no mention of case-insensitive fallback.

What changed:
- src/mcp/mcp.c TOOLS[] (classic mode, line 287): name_pattern and qn_pattern
  gain description: "Regex pattern on symbol name. Glob wildcards (*tool*,
  foo?) auto-convert to regex."
- src/mcp/mcp.c TOOLS[] (classic mode, line 329): trace_call_path tool
  description adds "Matches exact name first, then falls back to
  case-insensitive search if not found." function_name param gains
  "Case-insensitive fallback if exact match not found."
- src/mcp/mcp.c STREAMLINED_TOOLS[] (line 447): same name_pattern/qn_pattern
  descriptions. sort_by gains description: "Sort order: relevance (PageRank,
  default), name, degree (edge weight), calls (function calls in+out),
  linkrank (link-based rank)."
- src/mcp/mcp.c STREAMLINED_TOOLS[] (line 472): same trace_call_path
  description and function_name param updates.

Why: After fixing three bugs (sort_by validation, glob auto-convert,
trace_call_path fuzzy fallback) in commit 77352a7, the tool schemas served
to AI clients did not describe the new behaviors. AI agents would still
write .*tool.* instead of *tool* (not knowing glob works), not know what
sort_by values mean in streamlined mode, and not know that function_name
matching is case-insensitive.

Testable: codebase-memory-mcp cli tools/list shows updated descriptions.
Signed-off-by: Andrew Hundt <ATHundt@gmail.com>

src/mcp/mcp.c

@@ -284,7 +284,10 @@ static const tool_def_t TOOLS[] = {
      "precise results in one call. When has_more=true, use offset+limit to paginate. "
      "Use mode=summary for quick codebase overview without individual results.",
      "{\"type\":\"object\",\"properties\":{\"project\":{\"type\":\"string\"},\"label\":{\"type\":"
-     "\"string\"},\"name_pattern\":{\"type\":\"string\"},\"qn_pattern\":{\"type\":\"string\"},"
+     "\"string\"},\"name_pattern\":{\"type\":\"string\",\"description\":\"Regex pattern on symbol "
+     "name. Glob wildcards (*tool*, foo?) auto-convert to regex.\"},"
+     "\"qn_pattern\":{\"type\":\"string\",\"description\":\"Regex pattern on qualified name. "
+     "Glob wildcards auto-convert to regex.\"},"
      "\"file_pattern\":{\"type\":\"string\"},\"relationship\":{\"type\":\"string\"},\"min_degree\":"
      "{\"type\":\"integer\"},\"max_degree\":{\"type\":\"integer\"},\"exclude_entry_points\":{"
      "\"type\":\"boolean\"},\"include_connected\":{\"type\":\"boolean\"},\"limit\":{\"type\":"
@@ -324,9 +327,12 @@ static const tool_def_t TOOLS[] = {
 
     {"trace_call_path",
      "Trace function call paths — who calls a function and what it calls. Use INSTEAD OF grep when "
-     "finding callers, dependencies, or impact analysis. Shows candidates array when function name "
+     "finding callers, dependencies, or impact analysis. Matches exact name first, then falls back "
+     "to case-insensitive search if not found. Shows candidates array when function name "
      "is ambiguous. Results are deduplicated (cycles don't inflate counts).",
-     "{\"type\":\"object\",\"properties\":{\"function_name\":{\"type\":\"string\"},\"project\":{"
+     "{\"type\":\"object\",\"properties\":{\"function_name\":{\"type\":\"string\","
+     "\"description\":\"Function name to trace. Case-insensitive fallback if exact match not found."
+     "\"},\"project\":{"
      "\"type\":\"string\"},\"direction\":{\"type\":\"string\",\"enum\":[\"inbound\",\"outbound\","
      "\"both\"],\"default\":\"both\"},\"depth\":{\"type\":\"integer\",\"default\":3},\"max_results"
      "\":{\"type\":\"integer\",\"description\":\"Max nodes per direction (configurable via "
@@ -441,9 +447,15 @@ static const tool_def_t STREAMLINED_TOOLS[] = {
      "'dep'/'deps' (dependencies only), 'dep.pandas' (specific dep), glob patterns.\"},"
      "\"cypher\":{\"type\":\"string\",\"description\":\"Cypher query for complex multi-hop "
      "patterns. When provided, other filter params are ignored. Add LIMIT.\"},"
-     "\"label\":{\"type\":\"string\"},\"name_pattern\":{\"type\":\"string\"},"
-     "\"qn_pattern\":{\"type\":\"string\"},\"file_pattern\":{\"type\":\"string\"},"
-     "\"sort_by\":{\"type\":\"string\",\"enum\":[\"relevance\",\"name\",\"degree\",\"calls\",\"linkrank\"]},"
+     "\"label\":{\"type\":\"string\"},"
+     "\"name_pattern\":{\"type\":\"string\",\"description\":\"Regex pattern on symbol name. "
+     "Glob wildcards (*tool*, foo?) auto-convert to regex.\"},"
+     "\"qn_pattern\":{\"type\":\"string\",\"description\":\"Regex pattern on qualified name. "
+     "Glob wildcards auto-convert to regex.\"},"
+     "\"file_pattern\":{\"type\":\"string\"},"
+     "\"sort_by\":{\"type\":\"string\",\"enum\":[\"relevance\",\"name\",\"degree\",\"calls\",\"linkrank\"],"
+     "\"description\":\"Sort order: relevance (PageRank, default), name, degree (edge weight), "
+     "calls (function calls in+out), linkrank (link-based rank).\"},"
      "\"mode\":{\"type\":\"string\",\"enum\":[\"full\",\"summary\"]},"
      "\"compact\":{\"type\":\"boolean\"},\"include_dependencies\":{\"type\":\"boolean\"},"
      "\"limit\":{\"type\":\"integer\"},\"offset\":{\"type\":\"integer\"},"
@@ -460,11 +472,13 @@ static const tool_def_t STREAMLINED_TOOLS[] = {
      "Trace function call paths — who calls a function and what it calls. "
      "Use for impact analysis, understanding callers, and finding dependencies. "
      "Auto-indexes the project on first use if not already indexed. "
+     "Matches exact name first, then falls back to case-insensitive search if not found. "
      "Results sorted by PageRank within each hop level. depth < 1 clamped to 1. "
      "direction must be inbound, outbound, or both (invalid values return error). "
      "Read codebase://architecture for key functions to start tracing from.",
      "{\"type\":\"object\",\"properties\":{"
-     "\"function_name\":{\"type\":\"string\",\"description\":\"Function name to trace\"},"
+     "\"function_name\":{\"type\":\"string\",\"description\":\"Function name to trace. "
+     "Case-insensitive fallback if exact match not found.\"},"
      "\"project\":{\"type\":\"string\"},"
      "\"direction\":{\"type\":\"string\",\"enum\":[\"inbound\",\"outbound\",\"both\"]},"
      "\"depth\":{\"type\":\"integer\",\"default\":3},"