Implement INPUTNAME string opcodes

docs/engine-re.md

@@ -2891,6 +2891,13 @@ character cells, copies that text into both `0x144` operands, then calls `0x2c6`
 the VM worker blocks while Godot's main thread presents a LineEdit dialog, validates the CP932 byte limit
 and full-width-only rule, and signals the worker on accept or cancel. No save/profile format is involved.
 
+**Port implementation (2026-07-29).** `Cp932Text` now owns the byte-level character count, substring,
+and AGERC acceptance rules. The VM dispatches all three handlers and exposes the modal as an explicit
+accept/cancel `IHost` exchange, so cancellation cannot overwrite operand 1. Godot uses a main-thread
+`FullwidthTextEditorDialog` while its VM worker waits; over-16-byte and non-double-byte submissions retain
+focus and show AGERC's exact Japanese errors. The helper operates on the C-string prefix and encodes through
+the configured native code page, avoiding both UTF-16 indexing and accidental splitting of CP932 pairs.
+
 `0xc2` is BGM rather than SFX: `op_0xc2_bgm_fade@0x4204c0` sets run-state `0x200`, arms the service timer,
 and calls `bgm_fade_arm@0x464830`. `bgm_fade_tick@0x464960` linearly interpolates current to target percent;
 durations at least 1000 ms take 100 steps, shorter durations take 10, and target zero releases the source.

docs/opcode-reference.md

@@ -423,14 +423,14 @@ This is raw strlen(bytes), not a .NET UTF-16 character count. BUNKI compares all
 - **grounding:** source=investigation, confidence=high
 - **evidence:** The real /v2 dispatch slot registers op_0x2c6_cp932_character_length@0x42a6d0. The handler sets LC_ALL to `japanese`, resolves operand 2, calls MSVC _mbstrlen, and writes the result to operand 1. INPUTNAME's sole site at 0x1002 uses this count as the loop bound before slicing each character with opcode 0x2c8.
 
-This is character count rather than .NET UTF-16 length or raw CP932 byte length. The implementation should use VmOptions.NativeStringCodePage and preserve valid CP932 multibyte boundaries.
+This is character count rather than .NET UTF-16 length or raw CP932 byte length. Port status (2026-07-29): implemented by encoding the C-string prefix through VmOptions.NativeStringCodePage and counting valid CP932 lead/trail pairs as one character; focused tests cover mixed single-byte and double-byte characters.
 
 ### 0x2c8 `cp932-substring` (cp932-substring, argc 4)
 - **summary:** (out)(string)(start)(count) - copy a CP932 substring selected by multibyte-character index and count without splitting valid lead/trail pairs.
 - **grounding:** source=investigation, confidence=high
 - **evidence:** The real /v2 dispatch slot registers op_0x2c8_cp932_substring@0x42c420. It copies operand 2 into a 256-byte buffer, sets LC_ALL to `japanese`, obtains _mbstrlen, reads start and count, clamps end=start+count to the character length when end is below 1 or beyond that length, and walks bytes with _mbbtype so CP932 lead/trail pairs are copied together. It writes the selected byte interval back through operand 1. INPUTNAME's sole site at 0x1021 loops substring(name,index,1) into its eight local character cells.
 
-The release call uses nonnegative in-range indices and count 1. A compatible general implementation should reproduce native end clamping (`end = length` when start+count < 1 or > length) and select the half-open character interval [start,end).
+The release call uses nonnegative in-range indices and count 1. Port status (2026-07-29): implemented over encoded byte spans, preserving every valid lead/trail pair and reproducing native end clamping (`end = length` when start+count < 1 or > length) before selecting the half-open character interval [start,end).
 
 ## control
 
@@ -1256,6 +1256,11 @@ character palette. The VM can use a synchronous host seam like the existing diag
 the Godot host runs script execution on its worker thread while the main thread owns the modal UI.
 Compatibility requires the native full-width-only and 16-CP932-byte limits before accepting the result.
 
+Port status (2026-07-29): implemented. The VM issues an explicit accept/cancel request through IHost;
+headless hosts preserve the inout value by default. Godot parks the VM worker, opens a main-thread modal
+LineEdit, keeps it open on either native validation error, and resumes the worker only after valid accept
+or cancel. Accept replaces operand 1 and cancel leaves it untouched; operand 2 is never modified.
+
 
 ### 0x19a `get-message-skip` (u00414E50, argc 1)
 - **summary:** (out) - return the current all-message skip state set by op 0x88.

docs/phase-b-framework.md

@@ -930,6 +930,23 @@ gaps and 3 of 11 instructions; no persistence or save-format work is involved.
 **NEXT:** implement and test `0x144`/`0x2c6`/`0x2c8` together, including CP932 mixed-width helper cases,
 the native 16-byte/full-width acceptance rules, accept/cancel behavior, and INPUTNAME's split/rejoin shape.
 
+**INPUTNAME string/input slice implemented (2026-07-29):** the VM now dispatches all three opcodes.
+`0x2c6` counts CP932 characters rather than UTF-16 units or bytes, and `0x2c8` slices encoded character
+spans with native end clamping. A shared validator applies command 10's 16-byte limit first and then
+requires every accepted cell to be a valid CP932 lead/trail pair.
+
+`0x144` uses an explicit synchronous host result, preserving operand 1 on cancel and operand 2 in both
+paths. Godot parks the VM worker while a main-thread modal editor owns input; invalid submissions leave
+the editor open with AGERC's original error text. Headless hosts cancel safely by default. Focused
+regressions cover mixed-width count/slicing, end clamping, valid and invalid names, accept replacement,
+cancel preservation, and operand-2 preservation. The slice removes three gaps and three instructions,
+leaving 6 effectful opcodes / 8 instructions. Validation passes 493/493 engine tests, opcode and
+EngineCtx lint, a zero-warning Godot build, clean diff checking, and the Himegari-targeted threaded
+`SELFTEST OK`.
+
+**NEXT:** rerank the remaining six gaps; begin with the two-site `0x24d` and check whether adjacent
+`0x248` belongs to the same native subsystem before choosing the next implementation boundary.
+
 ## Later Phase B breadth
 
 **INIT data-semantics side track started (2026-07-22).** Before naming more gameplay state, the static