feat(cph): implement nested outline manifest and batch/combined export

ADR-0029 — nested outline manifest, supersedes ADR-0008's flat [[parts]]:
- cph-model: recursive loader over manifest.toml containers / element.toml
  leaves; Lesson.parts (pure elements, DFS order) + Lesson.outline (elements
  interleaved with section headings at their DFS-open position); rejects
  ambiguous/incomplete folders and root-vs-container table misplacement
- cph-diag: new DiagCode::ManifestMalformed for carrier-document structure
  errors (discharges an existing TODO)
- cph-typst: augmented manifest now serializes the outline (element/section
  entries) instead of a flat parts array
- render/lib.typ: render-lesson renders section headings at their depth
- examples/TH-141 migrated to 5 nested section containers + 3 root segments,
  byte-identical element order; smoke-verified via cph check/build + pdftotext

ADR-0030 — batch & combined export, extends ADR-0009/0011:
- cph build with no --target batches every declared target (repeatable
  --target for an explicit subset); any target failure => non-zero exit,
  per-target ledger, independent per-target execution
- cph-model: bundle.toml loader (directory + [info]/[targets.*]/ordered
  lessons with per-lesson target overrides)
- cph-typst: augmented bundle manifest (path-prefixed member outlines),
  Engine::{compile_check_bundle,build_bundle_pdf}
- render/lib.typ: render-bundle assembles member lessons under per-lesson
  headings, depth-shifts their own section headings, resets example/lemma
  counters at each lesson boundary by default
- cph-cli: `cph bundle <path> --target <name>` subcommand, same batching
  contract as `cph build`
- new bundle fixtures/tests (cph-model unit + cph-typst through-template PDF
  compile), smoke-verified via a real 2-lesson merged PDF

Verification: cargo fmt/clippy/test clean across the workspace (68 tests);
real cph check/build/bundle runs against TH-141 and a bundle fixture, PDF
content inspected via pdftotext.

examples/TH-141/固液界面/segments/浸润全谱与高低能表面/element.toml

@@ -0,0 +1 @@
+kind = "segment"

examples/TH-141/固液界面/segments/浸润全谱与高低能表面/textbook.typ

@@ -0,0 +1,17 @@
+由 @GGZ判据 按 $r equiv gamma_(S G) \/ gamma_(L G)$ 切段：
+
+#figure(
+  table(
+    columns: (auto, auto, auto),
+    align: (left, left, left),
+    table.header[*比值范围*][*接触角*][*现象*],
+    [$r > 1$], [无解], [完全铺展（superwetting）],
+    [$r = 1$], [$theta = 0$], [临界完全浸润],
+    [$1\/4 < r < 1$], [$0 < theta < pi\/2$], [部分浸润],
+    [$r = 1\/4$], [$theta = pi\/2$], [临界不浸润],
+    [$r < 1\/4$], [$theta > pi\/2$], [不浸润、成珠状],
+  ),
+  caption: [浸润全谱]
+) <浸润全谱表>
+
+把 @γ量级表 与浸润全谱并置就得到日常现象的解释。高能表面如金属、清洁玻璃，$gamma_(S G) tilde.op 1 thin "J/m"^2$，远大于水的 $gamma_(L G) tilde.op 0.072 thin "J/m"^2$，$r >> 1$，水在其上完全铺展。低能表面如石蜡、Teflon，$gamma_(S G) tilde.op 0.02 thin "J/m"^2$ 小于水的 $gamma_(L G)$，$r < 1\/4$，水在其上不浸润、成珠状。"水在玻璃上铺、在荷叶上成珠"这两件日常现象就是 $r$ 取值在 @GGZ判据 中位于 $r >> 1$ 与 $r < 1\/4$ 两端的直接体现。