Add Claude Code Prompt Suggestions deep-dive (10-prompt-suggestions.md)

* Add Claude Code Prompt Suggestions deep-dive as standalone doc (+290 lines)

New file docs/tools/claude-code/08-prompt-suggestions.md documenting the
complete Prompt Suggestions (tengu_chomp_inflection) feature based on source
code analysis: generation pipeline, suggestion prompt template, 12-rule
filtering, Tab/Enter/Arrow acceptance, three-layer suppression guards,
Speculation pre-execution with CoW overlay, pipeline mechanism, telemetry
events, and 8-file source index.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Rename to 10-prompt-suggestions.md (avoid numbering conflict with 08/09)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Add 10-prompt-suggestions to README.md index

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address review feedback: add source disclaimer, fix --bare vs -p, fix PR ref

- Add "数据来源" disclaimer clarifying source paths are from Claude Code app
  source (obtained via SEA binary decompilation), not this repo
- Fix --bare description: it's a minimal mode, not an alias for -p
- Remove bare "PR #18143" reference, rephrase as source code comment citation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address review: clarify env var three-state logic and timestamp default values

- Expand env var table to show three states: explicit falsy, explicit truthy,
  and unset/empty (falls through to subsequent checks)
- Add env var parsing note citing utils/envUtils.ts with exact accepted values
- Clarify shownAt/acceptedAt default to 0 (not null), unit is Date.now() ms,
  and acceptance check uses acceptedAt > shownAt

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address qwen3.6-plus-preview R1+R2 review: 10 fixes

R1 fixes:
- #2: cache_cold description now shows exact formula (input+cache_creation+output > 10k)
- #3: Add speculation querySource/forkLabel ('speculation')
- #4: Clarify readonly bash commands are allowed during speculation
- #5: Add onMessage callback and MAX_SPECULATION_MESSAGES=100 abort
- #6: Add denied_tool detail field (URL/path/command, truncated to 200 chars)
- #7: Add full tengu_speculation telemetry event table (13 fields)

R2 fixes:
- R2-1: Add speculation feedback message ([ANT-ONLY] ... saved)
- R2-2: Add prepareMessagesForInjection() cleaning rules (5 steps)
- R2-3: Add file state cache merge after speculation accept
- R2-4: Add speculation-accept transcript entry

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Address qwen3.6-plus-preview R3 review: 7 fixes

- R3-1: tools_executed counts tool_result && !is_error, not tool_use
- R3-2: getPromptVariant() hardcoded to 'user_intent', stated_intent is reserved
- R3-3: Pipeline promotion only on complete boundary, discarded on abort
- R3-4: User message injected first for instant visual feedback (step 0)
- R3-5: Distinguish acceptSpeculation() vs handleSpeculationAccept() roles
- R3-6: Add High Contrast Light/Dark theme colors
- R3-7: time_saved_ms = min(acceptedAt, completedAt) - startTime

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: wenshao