chore: add migration/ bundle for cross-machine setup

Bundles state that lives OUTSIDE the xenia-rs repo so a fresh clone on
another machine can be brought up to identical configuration via
migration/setup.sh:

  - claude-memory/             ~/.claude/projects/-home-fabi-RE-Project-Sylpheed/memory/
                               (103 files, 1.1 MB - MEMORY.md + every
                                project_xenia_rs_*.md from audits
                                addis_signext through audit-058)
  - project-root/dot-claude/   <project-root>/.claude/settings.json
                               (Stop hook + permissions)
  - project-root/ppc-manual/   <project-root>/ppc-manual/
                               (PowerPC reference docs, 397 files, 3.7 MB)
  - project-root/run-canary.sh <project-root>/run-canary.sh
  - README.md                  Human-readable setup checklist
  - setup.sh                   Idempotent installer (also reclones
                               xenia-canary at pinned HEAD 6de80dffe)
  - MANIFEST.md                Per-file mapping + per-file-not-bundled
                               restoration recipe

Excluded from bundle (not shippable via git):
  - Sylpheed ISO (7.8 GB; copyright; manual copy required)
  - sylpheed.db (395 MB; regenerable from XEX via analysis tooling)
  - target/ build artifacts (rebuild on target)
  - audit-runs probe firehoses (.log/.stdout/.stderr ~11 GB; rerun if needed)
  - audit-runs memory dumps (.bin ~4.5 GB; rerun audit-026/027/029 if needed)
  - xenia-canary checkout (setup.sh reclones from
    git.mc02.dev/fabi/Xenia-Canary.git at HEAD 6de80dffe)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

migration/project-root/ppc-manual/memory/dcbt.md

@@ -0,0 +1,117 @@
+# `dcbt` — Data Cache Block Touch
+
+> **Category:** [Memory](../categories/memory.md) · **Form:** [X](../forms/X.md) · **Opcode:** `0x7c00022c`
+
+<!-- GENERATED: BEGIN -->
+
+## Assembler Mnemonics
+
+| Mnemonic | XML entry | Flags | Description |
+| --- | --- | --- | --- |
+| `dcbt` | `dcbt` | — | Data Cache Block Touch |
+
+## Syntax
+
+```asm
+dcbt [RA0], [RB]
+```
+
+## Encoding
+
+### `dcbt` — form `X`
+
+- **Opcode word:** `0x7c00022c`
+- **Primary opcode (bits 0–5):** `31`
+- **Extended opcode:** `278`
+- **Synchronising:** no
+
+| Bits | Field | Meaning |
+| --- | --- | --- |
+| 0–5 | `OPCD` | primary opcode |
+| 6–10 | `RT/FRT/VRT` | destination |
+| 11–15 | `RA/FRA/VRA` | source A |
+| 16–20 | `RB/FRB/VRB` | source B |
+| 21–30 | `XO` | extended opcode (10 bits) |
+| 31 | `Rc` | record-form flag |
+
+## Operands
+
+| Field | Role | Description |
+| --- | --- | --- |
+| `RA0` | dcbt: read | Source GPR; when the encoded register number is 0 the operand is the literal 64-bit zero, **not** `r0`. |
+| `RB` | dcbt: read | Source GPR. |
+
+## Register Effects
+
+### `dcbt`
+
+- **Reads (always):** `RA0`, `RB`
+- **Reads (conditional):** _none_
+- **Writes (always):** _none_
+- **Writes (conditional):** _none_
+
+## Status-Register Effects
+
+_No condition-register or status-register effects._
+
+## Operation (pseudocode)
+
+```
+; Pseudocode derives directly from the xenia-rs interpreter
+; arm (see Implementation References). Operation semantics:
+;   - Read source operands from the fields listed under Operands.
+;   - Apply the arithmetic / logical / memory action described
+;     in the Description field above.
+;   - Write results to the destination register(s); update any
+;     status bits enumerated under Status-Register Effects.
+; Consult the IBM AIX reference link under IBM Reference for
+; canonical PPC-style pseudocode where xenia's expression is
+; terse.
+```
+
+## C Translation Example
+
+```c
+/* C translation: the xenia-rs interpreter arm below in           */
+/* Implementation References is the authoritative semantic        */
+/* snapshot. Translate it line-by-line:                            */
+/*   - ctx.gpr[N]  -> r[N]       (or f[]/v[] for FPRs/VRs)        */
+/*   - mem.read_u*/write_u* -> mem_read_u*_be / mem_write_u*_be   */
+/*   - ctx.update_cr_signed(fld, v) -> update_cr_signed(fld, v)   */
+/*   - ctx.xer_ca / xer_ov / xer_so -> xer.CA / xer.OV / xer.SO   */
+/* The Register Effects and Status-Register Effects tables above  */
+/* enumerate every side effect a faithful translation must emit.  */
+```
+
+## Implementation References
+
+**`dcbt`**
+- xenia-canary XML: [`tools/ppc-instructions.xml` — search for `mnem="dcbt"`](../../xenia-canary/tools/ppc-instructions.xml)
+- xenia-canary emit: [`src/xenia/cpu/ppc/ppc_emit_memory.cc:1142`](../../xenia-canary/src/xenia/cpu/ppc/ppc_emit_memory.cc#L1142)
+- xenia-rs opcode: [`crates/xenia-cpu/src/opcode.rs:19`](../../xenia-rs/crates/xenia-cpu/src/opcode.rs#L19)
+- xenia-rs decoder: [`crates/xenia-cpu/src/decoder.rs:794`](../../xenia-rs/crates/xenia-cpu/src/decoder.rs#L794)
+
+<!-- GENERATED: END -->
+
+## Special Cases & Edge Conditions
+
+- **Hint, not a guarantee.** `dcbt` requests that the cache line containing `EA` be brought into L1 in anticipation of a future load. The processor is free to ignore the hint (e.g. under cache pressure or for non-cacheable storage).
+- **Read-intent prefetch.** Pair-mate of [`dcbtst`](dcbtst.md) (which signals write intent and may prefer an exclusive cache state). Use `dcbt` when the next access is a read.
+- **No exception on bad address.** Unlike a real load, `dcbt` to an unmapped or protected page does not raise; the hint is silently dropped. This makes it safe to "speculatively" prefetch one line past the end of a buffer.
+- **Cache line size.** Xenon line is 128 bytes; low seven bits of `EA` are ignored.
+- **`RA0` semantics.** `RA = 0` selects literal zero — `dcbt 0, RB` prefetches the line containing address `RB`.
+- **Stream-engine hints.** The Xenon supports up to four hardware data-streams set up by sequences of `dcbt` with a stride; refer to the XDK for the stream-engine encoding (uses bits ignored by the architectural decode).
+- **Xenia treats as no-op.** Hints have no observable effect under the emulated memory model.
+- **Unprivileged.** Always available.
+
+## Related Instructions
+
+- [`dcbtst`](dcbtst.md) — write-intent prefetch.
+- [`dcbf`](dcbf.md), [`dcbst`](dcbst.md), [`dcbi`](dcbi.md) — push / invalidate counterparts.
+- [`dcbz`](dcbz.md), `dcbz128` — allocate-and-zero (a stronger "I want this line" signal).
+- [`icbi`](icbi.md) — instruction-cache analog (no instruction-cache prefetch in PowerPC).
+
+## IBM Reference
+
+- [AIX 7.3 — `dcbt` (Data Cache Block Touch)](https://www.ibm.com/docs/en/aix/7.3.0?topic=set-dcbt-data-cache-block-touch-instruction)
+- `PowerISA v2.07B Book II` § "Storage Control Instructions" for hint semantics.