fix: Go ingestion migration batch 5 (Parser 1.1/1.7/2.11, Chunker 1.7/1.8/2.6/2.7, Tokenizer 6x fixes) (#17419)

## Summary

Continuation of the Python→Go ingestion pipeline migration (File →
Parser → Chunker → Extractor → Tokenizer). Fixes cover Parser, Chunker,
and Tokenizer gaps identified. Fix page number (0-indexed and 1-index
mixed before fix; use 1-indexed after fix) and chunk order issues.

### Parser
- **Slides TCADP (1.7):** `pptx_tcadp.go` + TCADP branch in
`pptx_parser.go`/`ppt_parser.go` — PowerPoint files now support
`parse_method="tcadp"` via the TCADP cloud service, matching the
spreadsheet-family TCADP pattern. PPT containers pass `"PPT"` as
fileType (not hardcoded `"PPTX"`).
- **Audio default output_format (2.11):** `defaultSetups()` audio
default changed from `"text"` to `"json"`, aligning with Python
`parser.py:232` and `AllowedOutputFormat["audio"]={"json"}`.
- **PDF VLM enhancement (1.1):** `maybeDispatchPDFVisionEnhancement` in
`pdf_vision_dispatch.go` enriches image/table items with IMAGE2TEXT
model descriptions after PDF parsing, mirroring Python
`enhance_media_sections_with_vision`. Semaphore fix: acquire before
goroutine start to prevent unbounded goroutine creation.
- **json family (2.3):** reclassified as Keep Go — `json_parser.go` is a
functional enhancement, not a parity gap.
- **page number:** changed from "mixed use of 1-indexed & 0-indexed" to
"1-indexed"

### Chunker
- **BULLET_PATTERN fallback (1.7):** 4th-level fallback in
`resolveTitleLevels` (`title.go`) detects bullet/numbered-list patterns
(Chinese legal, numbering, English) when outline + regex levels produce
only bodyLevel. Guarded by `allBodyLevel` to never override existing
structure.
- **Tag/One chunker fields (1.8):** `tag.go` sets `TopInt` from source
row index; `one.go` preserves `Positions`/`PDFPositions` from source
items. TSV multi-line RowNum fix: tracks `contentStart` for correct row
attribution.
- **Overlapped_percent normalization (2.6):**
`NormalizeOverlappedPercent` in `schema/chunker.go` mirrors Python
`common/float_utils.py:50-58` — accepts `[0,1)` fraction or `[0,90]`
percent, normalizes to canonical `[0,90]`.
- **Paragraph splitting (2.7):** aligned to Python flow `naive_merge` —
`CRLF` normalization, `splitKeepingDelimiter` preserves sentence
delimiters, single-section merge with token-budget-governed chunking.
- **chunk order:** sort by reading order

### Tokenizer
- **Phantom chunk filtering (Omission 2):** `isPhantomChunk` + filter
loop in `chunksFromTokenizerUpstream` skips zero-value ChunkDocs.
- **Batch size env var (Omission 3):** `embeddingBatchSize()` reads
`TOKENIZER_EMBEDDING_BATCH_SIZE`, defaults to 16.
- **Summary empty check (Diff 5):** `TrimSpace(s) != ""` → `s != ""`,
matching Python truthy check.
- **chunk_order_int all paths (Diff 8):** set unconditionally before
full_text/embedding branching.
- **Timeout default (Diff 10):** `600s` → `60s`, matching Python
`@timeout(60)`.
- **Small maxTokens truncation (Diff 14):** `truncateForEmbedding`
returns `""` when `maxTokens <= 10`, matching Python.

### Code review fixes
- Semaphore acquire moved before goroutine in `pdf_vision_dispatch.go`
(concurrency control)
- Context propagation in `pptx_tcadp.go` (cancellation support)
- Test resolver leak fix in `media_dispatch_test.go` (defer restore)
- Migration history comments removed per AGENTS.md

## Test plan
```
bash build.sh --test ./internal/parser/parser/... ./internal/ingestion/component/...
```

## Notes
- Migration diff tracking: `docs/migration_python_go_diff.md`
- Remaining gaps: Extractor component only (21 items)

internal/parser/parser/ppt_parser.go

@@ -20,21 +20,32 @@ package parser
 
 import "context"
 
-type PPTParser struct{}
+// PPTParser delegates to PPTXParser which handles both OLE binary
+// (.ppt) and OOXML (.pptx) containers uniformly
+type PPTParser struct {
+	pptx PPTXParser
+}
 
 func NewPPTParser() *PPTParser {
-	return &PPTParser{}
+	return &PPTParser{pptx: PPTXParser{format: "ppt"}}
 }
 
 func (p *PPTParser) String() string {
 	return "PPTParser"
 }
 
+// ConfigureFromSetup forwards the slides-family setup map to the
+// underlying PPTXParser so both .ppt and .pptx containers share
+// the same TCADP configuration
+func (p *PPTParser) ConfigureFromSetup(setup map[string]any) {
+	p.pptx.ConfigureFromSetup(setup)
+}
+
 // ParseWithResult delegates to PPTXParser's structured output
 // for the legacy PPT format using the "ppt" container format
 // hint (OLE binary). The two file families differ only in the
 // binary container; the python parser.py:slides branch treats
 // them uniformly.
 func (p *PPTParser) ParseWithResult(ctx context.Context, filename string, data []byte) ParseResult {
-	return (&PPTXParser{format: "ppt"}).ParseWithResult(ctx, filename, data)
+	return p.pptx.ParseWithResult(ctx, filename, data)
 }