chore(release): 2.0.0-rc.3

[rahlk]

Cuts the [Unreleased] block to ## [v2.0.0-rc.3] and bumps version to 2.0.0-rc.3.

Analyzer pins carried by this release: codeanalyzer-java 3.1.0, codeanalyzer-typescript 1.5.0, codeanalyzer-python 1.4.1.

Verified before tagging:

• Full gate 1590 passed, 370 skipped, 85.13%, with both new analyzers actually installed.
• The block has five headings, 45 bullets and no duplicates — checked, since a doubled heading and duplicated bullets were a real mistake earlier in this line of work.
• Graph floors are unchanged and the claims about them are accurate: java 3.0.1, typescript 1.3.0, python 1.4.0. Both uptakes kept the floor and gated on data-measured probes instead of raising it.
• Two "re-analyse with " instructions now point at the pinned analyzer rather than a superseded release, so they cannot misdirect as pins move.