docs: feature-focused README refresh

step 2: simplify /start and /help message

step 1: filter status messages and strip technical metadata from telegram output

step 10: document TinyFish as optional future fetch backend

step 9: document signal scoring, optional Playwright, timeouts

step 8: travel keyword disclaimer when confidence below threshold

step 7: telegram typing indicator and long-silence heartbeat

step 6b: optional Playwright re-fetch when USE_PLAYWRIGHT_FETCH=1

step 6a: optional playwright requirements doc

step 5: structured run_start logging on API handlers

step 4: critic arbitration anchored to user goal for actionability

step 3: synthesis prompt nudge when high-signal sources low

step 2: fetch_page retries and browser-like headers

step 1: per-source low_signal heuristics and revised research_confidence

feat: Telegram bridge with live SSE, retries, longer timeout; docs and env template