perf(mcp)!: default to compact input schema advertisements (#5975)

Use compact MCP input advertisements by default while preserving explicit full, canonical validation, output contracts and complete Evidence. Require an explicit selected catalog for runtime identity and honor both profiles in CLI status.

Real ripgrep/Zellij SDK tasks, independent ELF oracle, actual client trials, profile parity workflows and CI are recorded in experiments/analysis-efficiency/mcp-input-catalog.md. SDK token estimates improve; actual Codex token savings and general latency/memory gains are not established.

Refs #5861

BREAKING CHANGE: MCP input advertisements default to compact. Set REA_MCP_INPUT_SCHEMA_PROFILE=full for complete advertised guidance and nested constraints.

docs/mcp-contracts.md

@@ -1020,14 +1020,15 @@ verify the compact advertisement through the same client boundary.
 
 Some function-calling providers reject a request while any single tool's
 `parameters` schema exceeds a literal serialized size cap; Moonshot clients
-such as kimi-cli fail every request while the default catalog is attached
+such as kimi-cli have reported failures with the full catalog attached
 ([#1484](https://github.com/morluto/rea/issues/1484)). Setting the server's
-`REA_MCP_INPUT_SCHEMA_PROFILE` environment variable to `compact` renders every
-advertised input schema within a 13,312-byte budget, measured to sit below
+`REA_MCP_INPUT_SCHEMA_PROFILE` environment variable to `compact` (the default)
+renders every advertised input schema within a 13,312-byte budget, measured to sit below
 Moonshot's observed cap (community measurements: a 13.7 KB schema is accepted
 while a ~15 KB one is rejected). The setting is read at startup; restart the
-server to apply changes, as with `REA_MCP_MAX_RESPONSE_BYTES`. The default
-value `full` keeps the complete advertisement unchanged. Compact presentation
+server to apply changes, as with `REA_MCP_MAX_RESPONSE_BYTES`. Explicitly select
+`full` to retain complete advertised input guidance and nested validation detail.
+Existing explicit profile choices are preserved. Compact presentation
 also reduces schemas whose expanded JSON tree exceeds ten levels, the limit
 reported by strict-depth MCP clients in [#2813](https://github.com/morluto/rea/issues/2813).
 WorkBuddy/CodeBuddy gateways have also rejected full REA catalogs with an