docs: update README skill counts to the 28 shipped skills

Baseline

main at 35bd5ecfcd84c8e457323a1bcf9453ba600c0270.

Problem

The two root READMEs advertise inconsistent and stale counts for the bundled skills:

• README.md: 26 in the introduction, 24 under “Agent-Native Design,” and 26 under “Wide Coverage.”
• README.zh.md: 26 in all three corresponding locations.

Both repository-backed checks report 28 top-level shipped skills:

(git ls-files 'skills/*/SKILL.md' | Measure-Object).Count
# 28

go run . skills list
# 28 listed entries

The “Agent Skills” tables are also incomplete: each has 23 rows and omits lark-apps plus the four compatibility entries lark-minutes, lark-note, lark-vc, and lark-vc-agent.

Expected behavior

The introductory counts should agree with the actual shipped skill set and with each other, and the skill tables should account for all 28 entries while identifying compatibility aliases as such.

Impact

The first product description users see understates the available skill set and gives different totals within the English page itself. The tables also hide the app-development skill and do not explain the four legacy names that the CLI still ships.

Suggested direction

Update the six stale literals from 24/26 to 28 and add the five missing table rows. A generated or checked count could prevent future drift, but the documentation correction can remain focused.

Duplicate check

I searched open and closed issues, all PR states, and recent commits for README skill counts and the exact 26 AI Agent Skills text. The earlier merged statistics correction #691 predates later skill additions; no current issue or open PR updates these counts or adds the five missing entries.

Start with the two root files, README.md and README.zh.md, and inspect the six skill-count literals and each 23-row Agent Skills table. Run git ls-files 'skills/*/SKILL.md' and go run . skills list to confirm the baseline. Done means both READMEs consistently describe 28 shipped skills and include rows for lark-apps and the four compatibility entries.