chore(release): bump version 0.9.65 -> 0.9.66

[LakshmanTurlapati]

Why

Routine release-prep version bump ahead of shipping the current batch of stats / telemetry-fix PRs (#54 chrome-extension.yml deps, #55 cumulative-commits chart) and any subsequent extension publish to the Chrome Web Store. Mirrors prior commit 858e692 (0.9.64 → 0.9.65) — identical file set and diff shape.

What

8 files, 14 line changes. All user-visible version surfaces move from 0.9.65 to 0.9.66:

File	Refs
package.json	3 (version, package script zip filename, badge URL)
extension/manifest.json	2 (name "FSB v0.9.66", version)
README.md	3 (title, badge, status banner)
extension/README.md	1
store-assets/chrome-web-store/listing-copy.md	1 (line 5 only — line 83 v0.9.69 milestone ref left untouched)
mcp/README.md	1 (line 534 cross-reference parenthetical)
showcase/angular/package.json	1
showcase/angular/package-lock.json	2 (top-level + packages[""].version)

What's NOT changed (deliberate)

• mcp/src/version.ts — FSB_MCP_VERSION = '0.9.0' is independently versioned per mcp/README.md:534. Never bumps with the extension.
• showcase/angular/src/app/core/seo/version.ts — auto-generated from extension/manifest.json by the prebuild script. Will regenerate on the next showcase build.
• Historical anchors — Phase 269 / v0.9.69, Phase 245 (v0.9.60), v0.9.62 visual-session contract, etc. — these are milestone-referenced source comments, not the current release marker. Untouched.
• listing-copy.md:83 — references v0.9.69 as the milestone the telemetry feature shipped under. Untouched.

Test plan

• All 4 modified JSON files parse via JSON.parse (exit 0).
• tests/mcp-version-parity.test.js → 10/10 PASS (no regression).
• grep -rn "0\.9\.65" across tracked source (excluding node_modules/.planning/dist/.git/.angular) → zero residual hits.
• mcp/src/version.ts unchanged at 0.9.0.
• CI green (extension, mcp, showcase all-green).
• Post-merge: showcase prebuild regenerates showcase/angular/src/app/core/seo/version.ts to 0.9.66 automatically.

Quick task

Tracked at .planning/quick/260514-x4s-bump-fsb-version-0-9-65-0-9-66-across-al/.