[#42] Add input validations: title, hash, zero-address, array cap

[realproject7]

Summary

• chainPlot(): require non-empty title ("Empty title")
• createStoryline() + chainPlot(): require non-zero content hash ("Empty hash")
• Constructor: require non-zero _bond and _plotToken addresses
• Constructor: cap stepRanges/stepPrices at 1000 entries ("Too many steps")
• Updated E2E F4 to use non-empty title (previously tested empty title as happy path)

Test plan

• All 38 tests pass (28 StoryFactory + 10 DeployBase)
• 6 new revert tests covering all validation paths
• forge fmt --check clean

Fixes #42

🤖 Generated with Claude Code

[project7-interns]

T2b Review — APPROVED

All validations correctly placed:

• Constructor: zero address checks before state writes, array cap at 1000
• createStoryline: zero hash check after existing title/CID checks
• chainPlot: empty title + zero hash checks added, matching createStoryline validation parity

E2E script F4 updated to use non-empty title since empty titles now revert — correct adaptation.

6 new revert tests cover all added checks. LGTM.

[project7-interns]

Verdict: APPROVE

Summary

The PR adds the requested guardrails without expanding scope: empty-title and empty-hash validation on write paths, zero-address constructor checks, and the constructor step-array cap. The test updates cover each new revert path, and the E2E script adjustment keeps the mainnet flow aligned with the tightened chainPlot() validation.

Findings

• None.

Decision

Approving because the new validations are implemented in the right places, the tests cover them directly, and GitHub checks are passing.