fix(tools): whole-sentence compact descriptions + front-loaded behavior disclosure

[heznpc]

Glama's TDQS scored the catalog C (avg 3.5/5, lowest 1.9/5) and the listing's
quality badge B. Root cause: compactDescription() kept the first sentence but
hard-capped it at 80 chars with slice(0,77)+"..." — every tool whose first
sentence ran past 80 shipped mid-word-truncated prose over the wire ("ending
with '...', indicating truncation" per the judge), and several short
descriptions disclosed nothing about behavior.

Mechanism (src/shared/tool-filter.ts, mirror synced in
scripts/measure-tool-tokens.mjs): keep as many leading COMPLETE sentences as
fit a 160-char budget; a boundary is sentence punctuation followed by
whitespace, so "etc.)", "e.g.," and version numbers don't split; only a first
sentence longer than the whole budget falls back to a word-boundary cut with
an ellipsis. Compact mode stays ON by default; AIRMCP_COMPACT_TOOLS=false
still returns full descriptions.

Content: front-load purpose + behavior in sentence one for the 14 lowest-
scoring definitions — 6 skill YAMLs (read/write nature + HITL gating now
disclosed up front instead of a tail "DESTRUCTIVE:" note the old cap never
let clients see) and 8 tools (update_reminder / create_folder /
capture_screenshot / create_shortcut / get_hourly_forecast enriched from
bare one-liners; semantic_index now front-loads "replaces any existing
index" and the real embedding requirement — GEMINI_API_KEY or the Swift
bridge, not bridge-only; find_related / summarize_context disclose read-only

• prerequisites). event_subscribe and spotlight_clear needed no text change —
  the mechanism fix alone un-truncates them.

Verified on a clean-room boot of the rebuilt dist: all 111 starter wire
descriptions are complete sentences <=160 chars, zero "..." endings.
New tests/tool-filter.test.js pins the wire contract (whole sentences,
word-boundary fallback, abbreviation safety, no mid-word cuts); suite 1929
pass. docs/tool-manifest.json + MCPIntents.swift regenerated — counts
unchanged (272 registerTool / 285 manifest / 232 intents; stats:check clean).