feat(predictive-echo): PredictiveEchoAddon + Layers 1-3 test suites (0.2.0)

Mosh-style write-through prediction: the consumer sends every keystroke
unchanged; the addon paints predicted glyphs and reconciles against the
parsed buffer. Confirm = cell match + cursor advance (placeholder-safe,
repaint-safe); two-pass mismatch cascade with neutral blanks (measured:
codex clears its placeholder on first echo); TTL bound; baseY-based line
reads; scroll/resize/off-row clears. Zero edits to zerolag-input-addon.ts.

Tests: 30 addon-law specs + renderer geometry (fake performance clock for
TTL/grace), 6 replay suites running the real algorithm through a real
@xterm/headless parser fed by the recorded codex fixtures, and a
500-iteration seeded fuzz with per-op span/record + grid invariants.
227 total, the pre-existing 175 untouched.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/xterm-zerolag-input/package.json

@@ -1,6 +1,6 @@
 {
   "name": "xterm-zerolag-input",
-  "version": "0.1.8",
+  "version": "0.2.0",
   "description": "Instant keystroke feedback overlay for xterm.js: Mosh-inspired local echo that removes perceived input latency over SSH, tunnels and other high-RTT connections",
   "type": "module",
   "main": "dist/index.cjs",
@@ -37,7 +37,9 @@
     "ssh",
     "remote-terminal",
     "overlay",
-    "addon"
+    "addon",
+    "predictive",
+    "write-through"
   ],
   "license": "MIT",
   "homepage": "https://github.com/Ark0N/Codeman/tree/master/packages/xterm-zerolag-input#readme",