build: the libavr pin advances past phase 6, at byte parity everywhere

The pin crosses libavr's phase 6 - the renamed system surface, the named
serial configs, the receiver-tolerance table, the paged SPM receipts -
and every loader image comes out size-identical: the full matrix on six
representative chips (the exhaustive cross product on three of them),
the stock and autobaud columns untouched, the four tsb tiers back on
their recorded floors at 510/526/638/836.

Byte parity was not free, and the two libavr defects it surfaced were
fixed there rather than absorbed here. The EEPROM write procedure's
step 2 - the SPMEN spin - had landed unconditionally and cost every
build six bytes for a wait a polled loader can never take; it is scoped
now, and the loaders state the datasheet's own omission clause
(spm_interlock::omitted, DS40002061B 8.6.3). The blocking page
erase/write grew an internal wait the tiers' settle() already provides,
so the tiers issue the command form and pureboot keeps its host-driven
sp_spm path.

What the port states rather than inherits: the stock 115200 at 16 MHz
sits +2.1 % past the receiver-tolerance table libavr now holds rates
to, so the hardware links say .allow_baud_error = true - the same
2.5 % envelope pureboot_baud_feasible() has always enforced, proven on
silicon across the fleet. rx_ready() reads readable() now.

Alongside the pin: rule 33's ASCII sweep over every source (docs keep
their typography), rule 34's InsertBraces in .clang-format with the
tree reformatted, std::array over the simavr runners' raw buffers, and
the stale Studio size in ide/README.md replaced by the claim its
check-flags gate actually holds.

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

test/pbtest.py

@@ -21,7 +21,7 @@ def fail(message):
 
 
 def rjmp_decode(word, at, flash_words):
-    """Where an rjmp word at word-address `at` lands — deliberately written
+    """Where an rjmp word at word-address `at` lands - deliberately written
     against the instruction-set definition (12-bit signed offset), not with
     the host tool's encoder, so an encoding bug cannot verify itself."""
     if word & 0xF000 != 0xC000:
@@ -86,7 +86,7 @@ def main():
                 fail(f"session 1 output lacks {needed!r}")
 
         # Session 2: reconnect into the live session, verify, dump, exercise
-        # the data space; hand over is deferred — the pty must be reopened for
+        # the data space; hand over is deferred - the pty must be reopened for
         # the APP banner first.
         probe = "c0ffee"
         out = pbsim.run_tool(tool, device.pty, baud, *extra, "--verify-flash", app_bin, "--verify-eeprom", ee_path,
@@ -123,7 +123,7 @@ def main():
             loader = pb.Loader(port)
             live = loader.connect(15)
             # The loader built from this tree must report a version the tool
-            # beside it speaks — a bump the tool was never told about is a
+            # beside it speaks - a bump the tool was never told about is a
             # loader it would refuse to talk to. Not equality with the newest:
             # the tool now spans two loader generations, the fixed-baud one
             # here and the unified autobaud loader that follows it.
@@ -139,7 +139,7 @@ def main():
             # rather than through write_page(), which would follow the fill
             # with its erase and write; the point here is that the fill alone
             # consumes exactly one page whatever the address's low bits say.
-            # Hand-sealed too — a protocol probe that borrowed the tool's own
+            # Hand-sealed too - a protocol probe that borrowed the tool's own
             # frame builder could not tell a wrong frame from a wrong loader.
             wire = base + 1
             head = bytes((pb.OP_FILL, pb.selector(pb.SP_FLASH, wire), wire & 0xFF,
@@ -156,8 +156,8 @@ def main():
 
             # And the seal itself, red: one wrong bit in the address of that
             # same frame must be refused outright. The verdict has to arrive
-            # *before* the page would have been sent — that ordering is what
-            # keeps a refusal from turning into a desync — so the probe sends
+            # *before* the page would have been sent - that ordering is what
+            # keeps a refusal from turning into a desync - so the probe sends
             # no payload at all and expects the loader straight back at the
             # command level.
             broken = bytearray(head + bytes((seal,)))
@@ -186,7 +186,7 @@ def main():
 
     # The surgery, decoded independently: the patched vector must land on the
     # loader, the trampoline on the application's own entry (patched-vector
-    # chips only — a boot-sectioned mega's word 0 stays the application's).
+    # chips only - a boot-sectioned mega's word 0 stays the application's).
     if patch:
         flash_words = (base + pb.SLOT) // 2
         app = open(app_bin, "rb").read()