docs: document scriptable trace access (on_frame, quiet, entries)

Adds a 'Structured / scriptable access' subsection under Live Sniff & Simulation covering the on_frame callback, quiet mode, the ANSI-free frame dict shape, and push vs pull (entries) usage for both SniffSession and SimSession.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -376,6 +376,56 @@ s.close()                                   # stop (if needed) and close the por
 
 A 14443-A sim path (`await s.start_14a(tag)`, WTX relay) also exists but is **async and experimental** — it requires the async `PM3Transport` (not the synchronous `SimSession.open()` port above) and is still under development.
 
+### Structured / scriptable access
+
+For scripting you usually want the frames as **data**, not printed colored text. Both
+`start_15693(...)` methods take two optional kwargs (defaults preserve the console
+behavior above):
+
+- **`on_frame=callback`** — invoked per decoded frame (from the reader thread) with a
+  plain dict. Passing it also auto-enables trace streaming on the sim.
+- **`quiet=True`** — don't print frames to the console (the callback and the `entries`
+  accumulator still fill).
+
+Every frame is an ANSI-free dict:
+
+```python
+{'protocol': int, 'direction': int,          # 0 = reader→tag, 1 = tag→reader
+ 'timestamp': int|None, 'duration': int|None,
+ 'data': bytes, 'data_hex': str,
+ 'decoded': str|None}                          # e.g. 'INVENTORY', 'READ BLOCK 4'
+```
+*(SimSession frames also carry `'crc_fail': bool`; sniff frames carry `timestamp`/`duration`.)*
+
+**Push model** — react to frames as they arrive, no printing:
+
+```python
+from pm3py.sniff.session import SniffSession
+
+reads = []
+s = SniffSession.open()
+s.start_15693(on_frame=lambda f: reads.append(f["decoded"]), quiet=True)
+# ... run a reader against a tag ...
+s.stop(); s.close()
+print(reads)     # ['INVENTORY', 'READ BLOCK 0', ...] — pure data, no ANSI
+```
+
+**Pull model** — run quiet, then read the accumulator afterward:
+
+```python
+from pm3py.sim import SimSession, IcodeSlix2Tag
+
+s = SimSession.open()
+s.start_15693(IcodeSlix2Tag(uid=None), trace=True, quiet=True)   # capture, no printing
+# ... phone reads the tag ...
+s.stop()
+for f in s.entries:                       # list of frame dicts (a copy)
+    print(f["direction"], f["data_hex"], f["decoded"])
+s.clear(); s.close()
+```
+
+`SimSession.entries` mirrors `SniffSession.entries`; both have `.clear()`.
+
 ### Card simulation
 
 The simulation framework (`pm3py/sim/` infrastructure, `pm3py/transponders/` tag models) provides pure-Python transponder models served from the firmware response table. Import everything from `pm3py.sim`.