fix(stats): lower k-anonymity floor from 5 to 2 so /stats shows real client names

[LakshmanTurlapati]

Summary

Lower K_ANONYMITY_FLOOR from 5 to 2 in showcase/server/src/telemetry/housekeeper.js so /stats can actually display MCP client names. At single-digit total install counts (currently 4), no real label can mathematically clear k=5, so every name collapses into Other and the chart stays empty.

Evidence (live prod, post all telemetry fixes from PRs #57, #59)

telemetry_events DB:

mcp_client	events	uniq_installs
OpenClaw	19	1
Claude	7	1
Codex	4	1
ChatGPT	3	1
unknown	93	4

/api/public-stats/global response:

{ "popular_mcp_clients": [{ "label": "Other", "uniq": 6 }] }

All four real labels (OpenClaw, Claude, Codex, ChatGPT) recorded correctly into telemetry_events post-PR #59. The k>=5 floor in housekeeper.js:97 then collapses every entry into the Other bucket because uniq=1 < 5. Even if every install converged on a single client, uniq would still be 4 and below k=5. Mathematically unreachable.

Change

- const K_ANONYMITY_FLOOR = 5;
+ const K_ANONYMITY_FLOOR = 2;

Per-label names still hide until a label reaches 2 distinct installs, so mild anonymity is preserved at the chosen k. Raise back to 5 once the total install count comfortably exceeds 50.

Test plan

• node tests/server-telemetry-housekeeper.test.js — 24/24 PASS (k=5 expectation updated to k=2: today's Claude+Codex both have uniq=1, aggregate below-k installs = 2, 2 >= k=2 -> single Other bucket with uniq=2).
• npm test (full root suite) — exit 0.
• Merge + deploy + wait for next housekeeper tick (hourly). Confirm /api/public-stats/global now lists at least one Other (uniq=N) entry or a real label if any client crosses k=2.

Operational follow-up

None. House-cleaning tick runs hourly on the deployed server; first re-aggregation after deploy will rewrite telemetry_global_aggregates.popular_mcp_json with the new floor.

🤖 Generated with Claude Code