Refine README Features table copy for consistency and scannability

[Copilot]

The README.md#features section was visually noisy due to mixed phrasing styles and unevenly long bullet text across modules. This PR tightens copy to improve table readability while preserving the original feature intent.

• What changed

  • Standardized bullet style across all 8 feature cards (Agent Loop, Kernel Tools, Permissions, Context & Memory, Gateway, Provider, Crash Recovery, Security).
  • Replaced mixed inline command-heavy wording with concise, plain-language labels where appropriate.
  • Normalized separators and phrasing (e.g., consistent use of A and B, X: Y, and compact noun phrases).

• Content adjustments by pattern

  • Shortened verbose lines without changing meaning (e.g., “Streaming tool-call cycle” → “Streaming tool-call loop”).
  • Converted implementation-detail wording into scan-friendly capability statements (e.g., “default - ...” → “Default: ...”).
  • Reduced punctuation/style variance that made rows look uneven.

• Representative diff snippet

  - **• `default` - prompt on write/shell**  
  - **• `auto` - allow all (CI/sandbox)**  
  - **• `plan` - read-only mode**  
  - **• Blocks `~/.ssh`, `~/.aws` reads**
  + **• Default: prompt on write/shell**  
  + **• Auto: allow all (CI/sandbox)**  
  + **• Plan: read-only mode**  
  + **• Blocks `~/.ssh` and `~/.aws` reads**

[zhimin-z]

要不我们不要现在的24的layout，变成33的layout，留一个empty的算了

[Copilot]

Pull request overview

This PR refines the copy in README.md’s Features section to improve consistency and scanability across the feature cards, without changing the underlying intent of the listed capabilities.

Changes:

• Standardized feature bullet phrasing to concise, plain-language labels across all feature cards.
• Normalized formatting patterns (e.g., “X and Y”, “Label: description”) and reduced command/tool-name heaviness.
• Tightened wording for readability (shorter lines, more uniform structure).

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[zhimin-z]

要不我们不要现在的2乘以4的layout，变成3乘以3的layout，留一个empty的算了

[zhimin-z]

要不我们不要现在的2乘以4的layout，变成3乘以3的layout，留一个empty的算了，修订feature table